共查询到19条相似文献,搜索用时 125 毫秒
1.
并网逆变器是分散式可再生能源接入配电网的重要接口,随着分布式可再生能源渗透率的不断提高,并网逆变器在传统配电网中的地位越发突出。为了高效完成可再生能源分散式并网,并有效降低并网逆变器对电网的冲击,一些在装置上、结构上和功能上更加先进的并网逆变器成为了迫切的需求。针对现有的一些先进并网逆变器进行比较、分析和研究,从装置级、功能级和控制级的角度对现有先进并网逆变器进行综述。给出一些在结构上能更加灵活地将可再生能源分散接入配电网的硬件电路。研究一些适用于可再生能源分散接入的,使并网逆变器能虚拟同步发电机完成自治运行、电能质量治理、系统阻抗检测、网络阻抗控制等辅助控制功能。同时还对并网逆变器的并网同步算法和电流跟踪控制策略进行了探讨。最后,提出一个适合于可再生能源分散并网的先进并网逆变器框架。 相似文献
2.
可再生能源分散接入用先进并网逆变器研究综述 总被引:9,自引:0,他引:9
并网逆变器是分散式可再生能源接入配电网的重要接口,随着分布式可再生能源渗透率的不断提高,并网逆变器在传统配电网中的地位越发突出。为了高效完成可再生能源分散式并网,并有效降低并网逆变器对电网的冲击,一些在装置上、结构上和功能上更加先进的并网逆变器成为了迫切的需求。针对现有的一些先进并网逆变器进行比较、分析和研究,从装置级、功能级和控制级的角度对现有先进并网逆变器进行综述。给出一些在结构上能更加灵活地将可再生能源分散接入配电网的硬件电路。研究一些适用于可再生能源分散接入的,使并网逆变器能虚拟同步发电机完成自治运行、电能质量治理、系统阻抗检测、网络阻抗控制等辅助控制功能。同时还对并网逆变器的并网同步算法和电流跟踪控制策略进行了探讨。最后,提出一个适合于可再生能源分散并网的先进并网逆变器框架。 相似文献
3.
本文基于可再生能源并网发电系统公共耦合点电压存在背景谐波,建立了并网逆变器的等效电路模型,解析了公共耦合点处电压背景谐波影响并网逆变器输出电流的机理,在控制环路中引入多谐振控制器改善了并网逆变器的输出电能质量,并给出了一种多谐振控制器参数设计的方法。最后,在仿真软件中搭建了可再生能源发电系统和配电网的模型,设定了电网背景谐波参数,分别进行了有无多谐振控制器控制策略的仿真实验,实验结果验证了本文采用的控制策略的正确性和可行性。 相似文献
4.
高比例可再生能源并网后,电力系统的运行场景更为复杂,电网阻抗变化及电网谐波等引起的电网不确定性严重影响了LCL型并网逆变器和电网稳定运行。为在弱电网条件下,使并网逆变器满足稳定性运行与电能质量要求,提出一种基于LCL参数优化设计的并网逆变器自适应控制方法。考虑控制系统延时特性,结合操作条件并利用奈氏判据计算出实际电网的最优参数形成一适应;针对弱电网的阻抗、频率带来的变化对比例谐振(PR)控制器进行改进形成二适应。工程结果验证了两个适应环节形成的自适应控制方法的有效性。在高比例可再生能源并网中有极大的应用前景。 相似文献
5.
6.
模拟同步发电机特性的同步逆变器研制 总被引:1,自引:0,他引:1
针对分布式可再生能源并网接口的先进控制策略,详细阐释了能使并网逆变器模拟传统同步发电机动态行为的同步逆变器技术。在同步发电机数学模型的基础上,给出了同步逆变器的控制策略,并深入讨论了同步逆变器参与电网调压和调频的能力,及其相应控制器参数的整定方法。通过将并网逆变器控制为同步逆变器,可以大大提升电网对含并网逆变器的分布式电源的接纳能力,降低传统并网逆变器对电网稳定带来的冲击。最后,利用1台10 k W的同步逆变器样机验证并网逆变器在模拟同步发电机特性、调节无功输出、以及参与电网调压和调频等方面的可行性和正确性。 相似文献
7.
8.
含逆变器的微电网动态相量模型 总被引:1,自引:0,他引:1
微电网作为一种分布式可再生能源并网的有效途径,是传统电力系统的重要补充。然而,微电网中含有大量的并网逆变器、机端负荷和线路,其电磁暂态过程给微电网的建模、分析和控制带来了巨大的挑战。以并网逆变器、线路和机端负荷的动态相量模型为基础,建立含并网逆变器的微电网动态相量模型。最后,在电磁暂态综合分析程序PSCAD/EMTDC中建立一个含有多台并网逆变器的微电网模型,并在Matlab/Simulink中建立其动态相量模型。仿真试验的结果验证了所提微电网动态相量模型的正确性和有效性,为并网逆变器和微电网的建模、分析和控制提供了一种新方法。 相似文献
9.
10.
11.
随着可再生能源在单相电网中渗透率的提高,电网对单相光伏并网逆变器提出了无功输出与功率因数灵活控制的要求。对HERIC(Highly Efficient and Reliable Inverter Concept)拓扑的无变压器隔离型单相光伏逆变器进行研究,提出了相应的无功调制策略。借助广义二阶积分构造两相静止坐标系,基于瞬时无功功率理论,建立了单相光伏逆变器的瞬时功率模型,实现了单相光伏逆变器的直接功率控制。搭建了5 k W的实验平台,通过实验对所提的调制策略与控制策略进行了有效性与实用性验证。 相似文献
12.
随着越来越多的分布式能源接入电网,并网逆变器获得了更多的应用。并网逆变器能够成功实现并网运行的前提是其直流母线电压高于最小要求限值,这限制了并网逆变器的应用。为降低并网逆变器的应用门槛,提出一种单相并网LCL型逆变器的改进设计方案。该设计方案通过将LCL型滤波器设计成一个有一定升压增益的模块,降低了前端逆变桥的输出电压要求,进而能够降低并网逆变器的直流母线电压限制,扩大了单相并网逆变器在低功率场合下的应用。首先分析传统LCL型单相并网逆变器直流母线电压受限制的原因,然后基于一种改进LCL型滤波器设计思路,利用其电压增益功能,给出一种详细的单相并网LCL型逆变器的改进设计方案,最后通过仿真和实验验证了提出的设计方案的有效性。 相似文献
13.
14.
15.
16.
针对高比例新能源电网的电压稳定问题和新能源脱网风险,新能源同步机(Motor Generator Pair,MGP)系统和调相机均能发挥重要作用。为对比二者的动态特性,本文介绍了MGP结构和控制策略,分析了MGP的无功调节原理和机械隔离作用。推导了调相机的动态调节特性及无功调节能力的影响参数。在PSCAD中分别搭建了MGP和调相机接入新能源并网系统的仿真模型,对比了不同故障情况下MGP和参数优化前、后调相机的动态特性,结果表明MGP和调相机都具备抑制电压跌落的能力,而MGP的机械隔离作用可以隔离故障对逆变器和新能源机组的大部分影响,防止新能源大量脱网。 相似文献
17.
FPGA‐based implementation for improved control scheme of grid‐connected PV system with 3‐phase 3‐level NPC‐VSI
下载免费PDF全文
![点击此处可从《International Journal of Circuit Theory and Applications》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Satabdy Jena Gayadhar Panda Rangababu Peesapati 《International Journal of Circuit Theory and Applications》2018,46(4):942-964
The large scale penetration of renewable energy resources has boosted the need of using improved control technique and modular power electronic converter structures for efficient and reliable operation of grid‐connected systems. This study investigates the performance of a grid‐connected 3‐phase 3‐level neutral‐point clamped voltage source inverter for renewable energy integration by using improved current control technique. For medium or high‐voltage grid interfacing, the multilevel inverter structure is generally used to reduce the voltage stress across the switching device as well as the harmonic distortion. The neutral‐point clamped voltage source inverter is controlled by using decoupling technique along with the proper grid synchronization via moving average filter–based phase‐locked loop. The moving average filter–based phase‐locked loop is used to reduce the delay in grid angle estimation under balanced as well as distorted grid conditions. A Lyapunov‐based approach for analysing the stability of the system has also been discussed. In this study, the hardware‐in‐loop (HIL) simulation of the control algorithm and the grid synchronization technique is realized using Virtex‐6 FPGA ML605 evaluation kit. The performance of the system is analyzed by conducting a time‐domain simulation in the Matlab/Simulink platform and its performance is examined in the HIL environment. The simulation and the hardware cosimulation results are presented to validate the effectiveness of the proposed control scheme. 相似文献
18.
We propose a novel inverter that can be operated either as a current source inverter (CSI) or as a voltage source inverter (VSI) by changing only the control signals. It is proper to use it for interconnecting systems with renewable energy, such as photovoltaic cells or wind generation systems, to a grid. This inverter is usually operated as a CSI connected to the grid. Even if the energy source has a lower voltage than the grid, energy can be supplied to the grid through the proposed inverter. The power factor can be brie?y maintained close to unity. When power supply from the grid is interrupted, the proposed circuit should be operated as a VSI in the stand‐alone operation mode. In this way, the circuit can maintain a constant output voltage to the loads. In this paper, the proposed circuit con?guration and the control schemes for both the CSI and the VSI are described. The circuit characteristics for both are also discussed experimentally. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 183(4): 45–53, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22349 相似文献
19.
Recent developments in power electronics technology have emerged towards the generation of electrical power from the renewable energy sources. Among renewable energy sources, solar energy has garnered more importance because of less maintenance and environmental friendly. In grid connected mode, distributed power generation system (DPGS) requires reliable islanding detection technique to find the electrical grid status and operate the grid connected inverter effectively. This paper investigates a comparative performance analysis of wavelet transform (WT) and wavelet packet transform (WPT) based detection in a three-phase grid connected PV inverter system under various power quality disturbances and islanding situation. The WT and WPT coefficients are determined by applying db4 wavelet basis functions, which are obtained optimally for analyzing perturbations that occur in grid connected PV system. The wavelet transform produces large errors due to spectral leakages in frequency bands. On the other hand, WPT provides uniform frequency subband with better time frequency resolution over WT. Finally, the feasibility of proposed WPT based islanding detection method is verified by simulating the system in MATLAB/SIMULINK environment. The simulated results demonstrate the better performance of WPT over WT technique and proved as an accurate, fast and reliable detection technique. 相似文献