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.     

DPC controlled three-phase active filter for power quality improvement

This paper presents a new control method entitled direct power control (DPC) for shunt active power filtering (5th, 7th, 11th, …) (SAPF), which is applied to eliminate line current harmonics and compensate reactive power. Its main goal is to rebuild active and reactive powers to be compared to references values using hysteresis control. The outputs of hysteresis controllers associated with a switching table, control the instantaneous active and reactive power by selecting the optimum switching state of the voltage source inverter (VSI). A theoretical analysis with a complete simulation of the system and experimental results are presented to prove the excellent performance of the proposed control technique.     

New hysteresis control band of an unified power quality conditioner

Power quality problems have received a great attention nowadays because of their economical impacts on both utilities and customers. The current harmonics is the most common problem of power quality, while voltage sags is the most severe. This paper deals with an Unified Power Quality Conditioner for current and voltage perturbations compensation in a power distribution network. The topology is based on two 3-phase voltage source inverters acting respectively as a parallel active power filter and a series active power filter which share two DC link capacitors. The power flow, in the Unified Power Quality Conditioner system is analysed. A novel hysteresis current and voltage control methods of Unified Power Quality Conditioner are studied with the aim to have robust control of the output voltage of series part and the output current of the parallel part. The DC voltage controller optimizes the energy storage of the DC capacitor where a fuzzy logic controller is developed. Simulation results are presented and discussed to verify the dynamical behaviour of the Unified Power Quality Conditioner and to show the effectiveness of the used perturbation identification methods and hysteresis band adaptive controllers.     

Power quality improvement using DPC controlled three-phase shunt active filter

This paper presents a new control method entitled direct power control (DPC) for shunt active power filter (APF), which is applied to eliminate line current harmonics and compensate reactive power. Its main goal is to rebuild active and reactive source powers to be compared to references values using hysteresis control. The active power reference is issue of DC-side of inverter and reactive power reference is set to zero for unity power factor. The outputs of hysteresis controllers associated with a switching table, control the instantaneous active and reactive power by selecting the optimum switching state of the voltage source inverter (VSI). A theoretical analysis with a complete simulation of the system and experimental results are presented to prove the excellent performance of the proposed technique.     

Coordination of multiple adjustable speed drives for power quality improvement

The proliferation of semiconductor-based non-linear devices in power systems has caused serious concern over power quality problems. This paper proposes a control strategy to coordinate multiple adjustable speed drives (ASDs) so that harmonic currents as well as reactive power generated by non-linear loads can be compensated. Under the proposed control strategy, the power quality improvement task is distributed to multiple adjustable speed drives and their contribution to the task is determined proportionally to their instantaneous power margins. The proposed control strategy can be a fairly flexible and economical solution for power quality improvement especially for the places where multiple machine drives are already-installed or required, for example, manufacturing factories or shipboard or aircraft power systems, because the adjustable speed drives can be fully utilized to improve power quality without additional compensators as well as conditioning end-use machines. Detailed simulation results using switching-level converter models verify the performance of the proposed coordination strategy.     

Analysis and comparison of premium power park performances

Premium power parks (PPP) are one possible answer to the need for high quality power supply for sensitive users. A few pilot plants based on Custom Power devices have been realized, but their cost and complexity are so high that they have not been widely adopted. However, the quality of the power supply can be improved with simpler solutions. This paper compares the performances of different PPPs by calculating the annual number of production process halts (PPH) due to the most impacting power quality (PQ) disturbances (interruptions and voltage dips, the latter classified according to the latest edition of EN 50160). The calculations are based on a large data set from Italian Medium Voltage (MV) networks. Aiming to look for practical PPP solutions, suitable assumptions are used to point out the efficacy of a relatively simple solution arrangement.     

电能质量问题及其治理前沿技术综述

研究电能质量问题的重大意义,并针对各种电能质量,从固态开关设备、储能设备以及静止补偿设备三大方面介绍了现有定制电力技术所采用的各种解决方案,提出了以统一电能质量控制器（UPQC）为核心装置的优质电力园区技术将成为未来配电网解决电能质量问题的发展方向。     

Three-phase,power quality improvement ac/dc converters

The generation of harmonics and reactive power flow in a power system is greatly influenced by the widespread use of power electronic converters in addition to other sources of harmonics and reactive power. The design, development and successful application of single-phase, power quality improvement converters in domestic, commercial and industrial environment has made possible the design and development of three-phase, power quality improvement converters and their widespread use in different applications. This paper deals with a comprehensive review of three-phase, power quality improvement converter configurations, control approaches, performance on supply and load sides in terms of input power factor, THD and well-regulated, reduced-rippled dc output, power rating, cost and selection for specific applications. It also provides state-of-the-art of power quality improvement converter technology to researchers, designers and engineers working on three-phase, switched-mode ac–dc converters.     

并联型有源滤波器自适应模糊控制方法研究

针对并联型有源滤波器滞环电流控制方法控制精度与开关损耗易受到滞环宽度的影响的问题,提出了一种自适应模糊滞环电流控制方法。首先通过模糊控制和锁相环技术得到参考电流,然后使用自适应模糊控制器产生指令电流。该控制方法使滞环带宽随着逆变器参数的变化自动调整,使其开关频率保持稳定,从而有效减少开关损耗,显著提高了有源滤波器的补偿性能。仿真和实验结果验证了所提方法的正确性和可行性。     

智能大厦电能质量问题及解决方案

为了保证智能大厦用电负荷的安全、稳定运行,同时减少其对电网的影响,在研究智能大厦用电负荷特点的基础上,针对智能大厦电能质量问题的特点,提出了一套治理电能质量问题的新型解决方案,该方案通过协调各种电能质量控制装置的运行状态使电能质量达到合理范围,从而实现电力资源的优质高价。     

Mathematical modelling of a wind power system with an integrated active filter

A novel technical solution of the power quality and electromagnetic compatibility (EMC) problems has been proposed through computer-aided design of a wind power system. In the considered wind power system, an AC power source generates the power, which is comparable to the consumed power. Consumer equipment is represented by a switch-mode power supply. Instead of the standard solution for the power quality and EMC problems, where a harmonic filter is placed between the load side and the wind-driven power generator, an active power filter has been integrated into the AC/DC/AC converter of the wind power system. A mathematical model of the AC/DC/AC converter built upon the multi-phase bridge-element concept has been introduced. A computer program for analysis of electromagnetic processes in a wind power system has been developed. A practical example of a wind power system has been analysed where the system frequency response is calculated using the developed mathematical model.     

基于电流预测控制的有源电力滤波器仿真研究

建立了并联有源滤波器的数学模型,引入电流预测控制方法,间接控制功率电路输出电流。提出了运用SISOTool辅助设计直流侧电容电压PI控制器,给出了设计的最终参数。通过Matlab的SimuLink仿真,证明预测控制的有效性及直流侧电压控制参数设定的合理性。     

Design and allocation of power system stabilizers using the particle swarm optimization technique for an interconnected power system

In this paper, three particle swarm optimization (PSO) based power system stabilizers (PSSs) are developed for three power systems. The system under study here is a power pool consisting of 3 power systems. System I represents the Egyptian power system, system II represents the Jordan and Syrian power systems, and system III for the Libyan power system, which are originally self standing and completely independent systems. As a matter of fact each of them should equipped with its own PSS. For this reason this work is started by designing an optimum power stabilizer for each of them standing alone. After which, the developed PSSs are firstly installed one at a time. Then the three PSSs are installed together in the interconnected power system and their effect on its dynamic performance is studied.As a test for stabilization efficiency, the detailed power system model is subjected to a forced outage of a 600-MW generator, which is the biggest unit in the pool, when it is fully loaded. This outage results in loosing of about 3% of the spinning capacity of system I and about 2% of the spinning capacity of the whole interconnected system. The obtained results show an improvement in the power pool performance accompanied with an improvement in the inter-area oscillation.     

Power quality evaluation in smart grids considering modern distortion in electric power systems

High power quality level is required in smart grids especially for non-stationary situations due to increased use of nonlinear loads and PQ disturbances such as dips, swells, transients and interruptions. Many power quality indices (PQIs) are available. In this paper a new fuzzy-wavelet packet transform-based power quality Index (FWPTPQI) is developed to amalgamate existing power quality indices as the output of a fuzzy based module based on fuzzy inference systems, knowledge base and existing PQI as input. Fuzzy systems allow handling the uncertainties associated with the electric power quality evaluation. The proposed approach has been applied to two case studies; stationary balanced and non-stationary unbalanced three-phase systems. The results are compatible with prevalent situations. The new index gives significant sense of the quality of transmitted electrical power. A comparative study of using different wavelet basis functions is considered and results indicate that Daubechies 10 and Daubechies 15 could be considered as the overall best wavelet basis functions. Since the new index represents an amalgamation of the PQ indices with less number of wavelet coefficients, it helps reduce the size of data processed which is required in smart grid applications.     

Simulations of wind power integration with complementary power system planning tools

This paper describes a procedure for simulations of wind power integration in a deregulated power system with two complementary planning tools. The first planning tool is a joint market model (JMM) taking into account the day-ahead market and the regulating power market using 1 h average time steps. The second tool is the stepwise power flow (SPF) model simulating the frequency deviations and power balancing within the hour, e.g. based on 5 min average time steps. Input data is shared by the two tools, and the simulation results from JMM are used in the SPF simulations to ensure consistent results. JMM simulations are performed using two different scenarios for the development in the Nordic power system. The first scenario is the most likely development for 2010, and the second is a high-wind scenario assuming 10% of the electricity consumption in the Nordic countries supplied by wind power. Subsequently, a worst case 1 h period is selected from the JMM simulations, converted to the more detailed grid representation in SPF, and finally simulated and analysed with SPF.     

基于ARM的远程电能质量监测系统

随着社会的进步和经济的快速发展,电能质量问题不断恶化,高效的电能质量监测变得越来越重要.从电力监测的实际要求出发,设计了基于ARM的电能质量综合监测系统,系统完成实时信号的采集,并利用嵌入式Linux自带的TCP/IP协议栈内建一个WEB服务器,工作人员可以在任何一个WEB浏览器访问这个系统.这对于地域跨越大的电网的远程监测提供了一种新思路.     

多模块并联有源电力滤波器的性能

对多模块并联的有源电力滤波器的几项关键技术进行了分析,包括负载电流采样分配策略、分流策略,提出了有效的解决方法,并设计了FUZZY-PI控制模块.利用Matlab软件对三模块并联的情况进行了仿真分析,并针对多模块并联系统可能出现的故障问题进行了仿真分析.仿真结果验证了方案的可行性.     

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。     

A power control scheme between quality control centers in FRIENDS

FRIENDS (Flexible, Reliable, and Intelligent Electrical eNergy Delivery System) is proposed as a new concept for a future power distribution system. One of the most important characteristics of FRIENDS is that of a QCC (Quality Control Center) as a new power quality control facility installed very close to customers. As one of the configurations of QCCs, an AC‐type QCC in which several distributed generators (DGs) can be installed easily has been proposed by the authors. In the FRIENDS concept, power exchange control between QCCs is included in case of a fault in upstream power systems for higher reliability and making good use of the power of distributed generators. A method to control several QCCs in case of a fault is proposed, and simulation results are presented. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 151(2): 20–31, 2005; Published online in Wiley InterScience ( www. interscience.wiley.com ). DOI 10.1002/eej.20040     

基于以太网的电能质量计算机监测系统设计

随着电力电子技术的快速发展,各种非线性设备被大量应用到生产实践当中,这些非线性和冲击性的负荷,严重影响着变电站的安全经济运行,导致电能污染日趋严重.因此,对电能质量进行在线监测,可以为改善电能质量、提出治理方案以及确定治理装置提供科学的依据,具有十分重要的意义.从电力监测的实际要求出发,设计了基于以太网的电能质量综合监测系统,介绍了系统的工作原理和各组成模块的设计,并通过实验验证了系统的可行性,对于地域跨越大的电网的远程监测提供了一种新思路.