基于改进MPPT算法的光伏并网系统控制策略  

Control strategy of grid-connected photovoltaic generation system based on modified MPPT method

作　　者：焦阳[1] 宋强[1] 刘文华[1] 

机构地区：[1]清华大学电力系统及发电设备控制和仿真国家重点实验室.北京100084

出　　处：《电力自动化设备》2010年第12期92-96,共5页Electric Power Automation Equipment

摘　　要：研究并改进了单相两级光伏并网发电系统的控制策略。以2种基本最大功率点跟踪(MPPT)技术为基础提出了一种结合固定电压法与增量电导法的占空比扰动MPPT算法。在不同的光伏电池运行点采用不同的跟踪方法,通过直接控制直流斩波器开关占空比以达到快速准确的功率跟踪效果。针对该算法的运行条件改进了光伏并网系统整体控制策略。通过直流电压外环的功率平衡控制及比例积分校正,配合内环并网电流反馈控制,使并网逆变器在保持并网电流质量的同时更好地控制直流电压。通过PSCAD/EMTDC软件搭建的光伏并网系统仿真模型验证了改进MPPT算法及逆变器控制策略的有效性。The control strategy of single-phase two-stage grid-connected PV（Photo Voltaic） generation system is studied and improved.A duty cycle perturbation MPPT（Maximum Power Point Tracking） algorithm is proposed based on two basic MPPT methods,which integrates CV（Constant Voltage） tracking and IC（Increment Conductance） tracking.Different tracking approaches are applied at different operating points and the duty cycle of DC chopper is directly controlled to achieve the optimum control results.The control strategy of PV generation system is improved to meet the requirements of the proposed algorithm.A DC voltage outer loop control for power balance and PI correction and an AC current inner loop control for feedback are designed to ensure the current quality and stabilize the DC voltage.A simulation system is built with PSCAD / EMTDC to verify the validity of the modified MPPT algorithm and the converter control strategy.

关 键 词：光伏发电系统 最大功率点跟踪 固定电压法 增量电导法 占空比扰动 变流器控制 PSCAD仿真 

分 类 号：TM464[电气工程—电器]