京沪高速铁路对江苏电网影响及治理措施

为研究高速电气化铁路接入江苏电网对电能质量的影响,以京沪高速铁路为例,分析了交-直-交型电力机车的负荷特点,基于ETAP软件平台建立了京沪高铁江苏段各牵引变电站及其周边网络的仿真模型,对谐波和负序进行定量评估,并针对电能质量问题,根据牵引侧三相SVC装置的补偿原理,提出了采用基于系统变换方法的动态无功补偿治理措施。结果表明,该方法谐波和负序补偿效果明显,各项指标均满足现行国标规定。     

Reactive power compensation and active filtering capability of WECS with DFIG without any over‐rating

This paper presents a novel approach for reactive power compensation and active filtering capability of a variable speed wind energy conversion system (WECS) with doubly fed induction generator (DFIG), without any over‐rating. First, the WECS is capable of capturing maximum wind power under fluctuating wind speed. Second, depending on the available wind power value versus nominal WECS power, power quality can be improved by compensating the reactive power and the grid harmonic currents, without any system over‐rating. The proposed rotor side converter (RSC) control manages the WECS function's priorities, between main active power generation and power quality management. To ensure high filtering performances, we used an improved harmonic isolator in the time domain, based on a selective pass band filter (SPBF) developed in our laboratory. Moreover, we took advantage of the high amplification effect of the rotor side‐controlled DFIG to compensate harmonic currents. Consequently, no over‐rating is necessary for the proposed additional active filtering capability. Simulation results for a 2 MW WECS with DFIG confirm the effectiveness and the performances of the proposed approach. Copyright © 2009 John Wiley & Sons, Ltd.     

Contribution to the improvement of voltage profile in electrical network with wind generator using SVC device

Wind energy is a growing renewable energy because of its several advantages; this has changed dramatically with more wind energy penetrating the conventional power network. The influence of wind generators on the power quality is becoming an important issue; non-uniform power production causes variations in system voltage and frequency, therefore, a wind farm requires high reactive power compensation. The advances in high power semiconductor devices have led to the development of Flexible AC Transmission System (FACTS). This paper presents the impact of wind energy integration on voltage stability and the goal of FACTS devices such as Static Var Compensator (SVC), which is a power electronic switch, to control the reactive power injection according to the thyristor firing angle, introduced as a state variable in power flow and combined with the nodal voltage magnitudes and angles of the power network for iterative solutions, thereby regulating the bus voltages.     

A new method for determining reference compensating currents of thethree-phase shunt active power filter

Among various solutions to electric power quality problems, the use of a shunt active power filter (SAPF) has been proven as an effective method to compensate reactive power and to mitigate harmonic currents of nonlinear loads. When designing a SAPF, it is crucial to generate reference currents for determining actual compensating current injections to the point of common coupling. In contrast to the conventional instantaneous reactive power theory that needs coordinate transformations, the new method proposed in this paper is to determine reference compensating currents based on the balance of the instantaneous reactive and active power generated in the SAPF. It is shown that the proposed method is suitable for reactive and harmonic power compensation by using a SAPF. In addition to maintaining the sinusoidal source currents, this method also eliminates the need for installing an energy storage device for reactive power compensation as well as the DC source for the harmonic compensation in the active power filter. Therefore, a simpler design of the SAPF with the minimal line losses can be expected     

大型钛渣冶炼电炉中谐波的产生与治理

介绍了钛渣冶炼工艺的电气特性,谐波产生的机理,并利用软件分析攀钢钛渣冶炼电炉的电能质量,对比了静态无功补偿与流行的动态无功补偿的优缺点,并根据加装SVC前后的测试数据证明了解决钛渣冶炼电炉存在的谐波问题需要采用现代流行的SVC装置进行治理。     

联合动态无功补偿系统在风电场中的应用研究

针对目前风电场单独采用静止无功补偿器（SVC）或静止无功发生器（SVG）的缺陷,设计了一个由大容量SVC和小容量SVG组成的联合动态无功补偿系统。首先,阐述了联合动态无功补偿系统的结构;其次,对本文采用的无功协调控制策略进行了分析;最后,结合实际风电场参数,对联合动态无功补偿系统进行了仿真实验分析。实验结果验证了联合动态无功补偿系统补偿的有效性和合理性。     

UPEC 2002 Preview

Using a shunt active power filter (SAPF) has been proved as an effective method to compensate reactive power and to mitigate harmonic currents of nonlinear loads. When designing a SAPF, it is crucial to generate reference currents for determining actual compensating current injections to the point of common coupling. In contrast to the conventional instantaneous reactive power theory, which needs coordinate transformations, the new method proposed in this letter is to determine reference compensating currents based on the balance of the instantaneous reactive and active power generated in the SAPF. It is shown that the proposed method is suitable for reactive and harmonic power compensation by using a SAPF In addition, to maintain the sinusoidal source currents this method also eliminates the need for installing energy storage devices for reactive power compensation as well as the DC source for the harmonic compensation in the active power filter. Therefore, a simpler design of the SAPF with minimal line losses can be expected.     

混合无功补偿系统分层控制策略

针对电能质量要求日益增加,为实现大容量低成本动态无功补偿,提出一种以静止无功补偿器(SVC)和静止无功发生器(SVG)协同运行的混合无功补偿系统,系统在充分利用SVG.SVC优势的基础上,构建一种基于频率分解的SVC+SVG的混合无功补偿分层控制模型。其中,功率协调层将无功指令电流进行分解,将频率较小的无功分量分配给SVC进行补偿,将频率较大的无功分量分配给SVG进行补偿;补偿控制层由于SVG处理的均为高频无功信号,使用自适应粒子群算法对SVG控制器进行PI参数整定;补偿执行层通过对SVC和SVG主电路发出无功电流,对电网无功功率进行补偿。Simulink仿真分析验证了所提控制策略的有效性,且相比于纯SVG补偿,成本有较大优势。     

Fuzzy multi-objective technique combined with VCS algorithm for unified power quality conditioner based on hybrid power source PEMFC/SC

This paper is proposed to establish an optimal control method for UPQC (Unified Power Quality Conditioner) to improve power quality and manage effectively equal power sharing between shunt and series inverter of UPQC under electrical faults condition. The UPQC is modeled to protect sensitive load from source side voltage disturbances under nonlinear load conditions. A hybrid power generator that integrates a proton exchange membrane fuel cell (PEMFC) as the main energy source and a super capacitor (SC) as secondary source is proposed to feed the FACT device. In this work, a new control strategy is presented for considering the voltage sag, power factor and total harmonic distortion (THD) as multi-objective of UPQC controller. For this purpose, a new powerful algorithm named virus colony search (VCS) is used for determining the coefficients of the PI controller of UPQC. By using the fuzzification process for the objectives function, a suitable fitness function is established for the optimization method. From the simulations, it can be seen that the results obtained by the proposed algorithm are best and attractive compared to other method. Consequently, the proposed strategy is effective and outstrips other strategies.     

Application and control of super capacitor in high-speed railway regenerative braking energy storage

针对高速列车在制动过程中产生的再生制动能量得不到有效利用的问题,提出一种基于超级电容（supercapacitor,SC）的高速铁路再生制动能量存储方案。该方案以铁路功率调节器（railway power conditioner,RPC）作为接口电路,将储能装置与牵引供电系统连接在一起,采用超级电容作为储能介质,通过双向DC/DC变流器与铁路功率调节器直流侧相连,从而实现能量存储与补偿负序电流的功能。在研究储能方案拓扑结构的基础上,分析了负序电流的补偿原理,并根据补偿原理研究了储能方案的控制策略,对RPC两变流器采用滞环控制的方法,对储能装置中的双向DC/DC变流器采用电流闭环的控制方法。仿真结果表明,所提出的存储方案能够有效回收利用高速列车产生的再生制动能,并对负序电流进行补偿,改善电网侧电能质量。     

电气化铁路中SVC负序补偿应用技术研究

随着电气化铁路的迅速发展,电铁牵引负荷产生的负序分量及高次谐波,除对牵引供电系统造成危害外,还会造成电力系统负序及谐波污染^[1],因而,电铁的负序及谐波危害已成为制约我国电气化铁路发展的重要因素。结合电气化铁路给电网带来的影响,着重探讨电铁负序补偿中SVC的使用问题。根据国外一些发达国家如日本、澳大利亚等国成功将SVC技术应用在电气化铁路的无功和负序补偿案例以及国内SVC负序补偿应用实例,对SVC负序补偿原理及运行方式进行了研究分析,对SVC在电铁负序治理中的应用前景做了初步探讨,以期提高电力系统运行的经济效益和社会效益。     

某钢铁公司电弧炉谐波治理方案研究

某钢铁公司电弧炉在运行过程中，总负荷的功率因数显著降低，并对电网产生谐波污染。为改善负荷情况，提高功率因数，兼顾谐波等电能质量问题，根据一种新型电能计测终端实测数据，制定了谐波治理兼无功补偿方案。仿真结果表明该方案的可行性和正确性。     

A multi-function grid-connected PV system with reactive power compensation for the grid

According to the theory of instantaneous reactive power, the active and reactive currents of inverter can be regulated by changing the amplitude and the phase of the output voltage of the inverter. Based on this theory, the active power output and the reactive power compensation (RPC) of the system are realized simultaneously at daylight. When the insolation is weak or the PV modules are inoperative at night, the RPC feature of PV system can still be used to improve the utilization factor of the system. The MATLAB simulation results validate the feasibility of the method.     

Modelling and investigation of clean power wind energy systems by using UPQC

This article presents a new clean power technique for wind energy system based on Unified Power Quality Conditioner (UPQC) with usage of various Artificial Intelligent techniques (AI). Application of AI techniques such as Artificial Neural Networks, Fuzzy Logic is growing fast in the area of power electronics equipment‐based wind energy system, for instance, UPQC. A novel control scheme is developed by using different AI techniques to mitigate the balancing issues and to control the power–quality problems in UPQC and hence to provide clean power to the grid. The proposed system is composed of shunt active power filter, and the inherent proportional integral (PI) control parameters are tuned with application of PI techniques. A detailed Matlab simulation study is carried out with an application of PI techniques under sag, swell, unbalanced, and harmonic conditions. An exhaustive simulation study is carried out to investigate the application of PI technique‐based controllers and compare its performance with the conventional PI controller with its results explored. Copyright © 2016 John Wiley & Sons, Ltd.     

Effects of FACTS controller line compensation on power systemstability

In this letter, the effects of line compensation of an SMIB power system using FC-TCR type TCSC or SVC for transient stability enhancement are analyzed. In particular, a novel method for analysis of line compensation by an SVC is presented. The maximum power transfer, P_emax for line compensation by FACTS controllers can be written in the form P_emax=P_max/(1-k) where P_max is the maximum power transfer for the uncompensated line and k is the degree of compensation. The analysis revealed that the effectiveness of the SVC for stability enhancement is increased if the degree of compensation of the line is increased     

基于ATP的电气化铁道供电系统不对称谐波分析

基于大量牵引负载谐波实测数据,分析了电气化铁道牵引负载谐波的分布特征,利用电磁暂态分析软件(ATP)建立牵引变电站220 kV地区供电系统元件的谐波计算模型,并对供电网络进行了不对称谐波潮流仿真计算.仿真结果与测量值比较,表明该方法对研究电气化铁道供电系统谐波分布行之有效.     

Effects of FACTS controller line compensation on power system stability

In this letter, the effects of line compensation of an single-machine infinite-bus power system using fixed-capacitor thyristor-controlled reactor-type or SVC for transient stability enhancement are analyzed. In particular, a novel method for analysis of line compensation by an SVC is presented. The maximum power transfer, for line compensation by FACTS controllers can be written in the form=(1-k) where is the maximum power transfer for the uncompensated line and k is the degree of compensation. The analysis revealed that the effectiveness of the SVC for stability enhancement is increased if the degree of compensation of the line is increased.     

青藏直流输电无功功率控制PSASP用户自定义建模

基于电力系统分析软件包PSASP,使用其用户自定义功能,建立了详细的无功功率控制模型。该模型为用户自定义高压直流输电模型的一部分,其参照青藏直流系统,并经适当简化而得。主要包括无功功率发生计算模块、无功功率消耗计算模块、无功功率控制模块及换流站无功功率调节控制模块,给出了每个模块的建模方法及建模原则。最后通过在WEPRI-7七节点系统,仿真验证了无功功率控制用户自定义模型对于交直流系统相互作用及稳定性分析的正确性及必要性。     

Rapid transaction to load variations of active filter supplied by PV system

This paper deals with the analysis and control of a photovoltaic (PV) system connected to the main supply through a Boost converter and shunt active filter supplied by a PV system providing continuous supply of nonlinear load in variation. A robust control of a PV system connected to the grid while feeding a variable nonlinear load is developed and highlighted. This development is based on the control of the Boost converter to extract the maximum power from the PV system using the Perturb and Observe (P and O) algorithm in the presence of temperature and illumination. The proposed modeling and control strategy provide power to the variable nonlinear load and facilitates the transfer of power from solar panel to the grid while improving the quality of energy (harmonic currents compensation, power factor compensation and dc bus voltage regulation). Validation of the developed model and control strategy is conducted using power system simulator Sim-Power System Blockset Matlab/Simulink. To demonstrate the effectiveness of the shunt active filter to load changes, the method of instantaneous power (pq theory) is used to identify harmonic currents. The obtained results show an accurate extraction of harmonic currents and perfect compensation of both reactive power and harmonic currents with a lower THD and in accordance with the IEEE-519 standard.     

Harmonic control using matrix converter of unbalanced input voltage supplied from solar power system

Most of the renewable energy sources are not distributed directly to consumer. It gone through several section to get optimum output voltage and current with the almost zero distortion. Direct Matrix converters are well known of its better power quality and low power distortion to the reactive loads. Conversely, multilevel H bridge inverters are broadly used to attain a sinusoidal output voltage in solar photovoltaic application. Reactive power is subject to high importance for the operation of alternating current (AC) power systems. Moreover there is always a challenge to obtain the balance current control from an unbalanced supply voltage with minimum harmonic distortion for reactive load application from solar power system. The main objective of the proposed system is to maximize the power usage by maintaining the current and power factor nearby unity. There are many different optimization techniques are used so far in matrix converter, a novel method of optimization BAT algorithm is proposed for the power quality to get the best result. This work mainly deals with the compensation of reactive power used in Solar Photovoltaic Power System. Bidirectional energy flow is possible with matrix converter for battery charging. Simulation results are presented to confirm the appropriate operation of the system under different of operating conditions. Also, in the proposed method the percentage of the higher order harmonics can reduced less than 9% of matrix converter for solar photovoltaic application.