【作者】 刘凤龙；

【导师】 高晗璎；

【作者基本信息】 哈尔滨理工大学 ， 电力电子与电力传动， 2010， 硕士

【摘要】 随着世界能源紧缺问题的日益严峻,太阳能作为国际公认的理想替代能源得到了越来越广泛的应用。但是太阳能发电系统普遍存在着太阳能光线吸收效率低、同等外界条件下光伏电池发电效率不能达到最大等问题,造成了太阳能资源以及太阳能发电设备的浪费。本文从上述的两个问题出发,提出了一种新型的太阳能光伏发电控制系统,从提高太阳光线的接收效率和光伏电池的输出功率两个方面来改善太阳能发电系统的工作效率。本文从太阳的对地运行规律出发,根据太阳光线的入射角度时刻变化的情况,提出了以光电检测跟踪方式,在俯仰-水平两个方向同时对太阳光线进行跟踪,使光伏电池板保持与太阳光线保持垂直,提高了光伏电池板的太阳光线接受效率。执行元件选择了两台三相混合式步进电动机,并针对其在传统的驱动方式下出现的低频振荡和噪声等问题,提出了均匀细分恒转矩控制方案,采用正弦波细分和电流跟踪型脉宽调制(SPWM)技术实现三相混合式步进电动机的细分控制。双轴跟踪和步进电机控制单元都以DSP(1) TMS320LF2407A为核心处理器,取得了良好的控制效果。在光伏发电系统中,光伏电池阵列输出特性具有非线性特征,而且其输出特性受光照强度、环境温度和负载情况影响。本文从最大功率点跟踪(MPPT)的基本原理和数学模型出发,分析了提高光伏电池输出功率的基本方法,提出了使用Cuk升降压电路来控制光伏系统的工作电压点,采用恒电压控制法(CVT)启动的变步长导纳增量法实现最大功率跟踪。系统以DSP(2) TMS320LF2407A为核心,完成了MPPT的相关运算,利用PWM波控制Cuk电路的开光管导通与关断,进而控制主电路电压。并采用MATLAB7.1进行仿真研究,仿真结果表明当日照环境发生变化时光伏电池的输出功率以及系统的响应速度和稳定性都得到了很大的提高,例如光伏电池被云层遮蔽的过程以及光照恢复时,系统均快速追踪到最大功率点,光伏电池以最大功率输出。更多还原

【Abstract】 As the worldwide energy shortage problem becoming increasing serious, solar as the ideal alternative energy recognized internationally is being used more and more widely. But the general solar system exists the low efficiency of solar light absorption and solar cell power in the same external environment, and the two problems results the waste of the solar resource and the solar power device. So a novel solar photovoltaic power control system was presented in this dissertation, which improved the working efficiency of the solar power system by improving the solar light absorption and the output of the solar cell.From the sun trajectory from the running regulation of the sun to the earth, a tracking method the photoelectric tracking method was proposed in this dissertation according to the varying at all times of incident angle of solar light. The method tracking the sun rays in both pitch-level directions, to keep solar panels perpendicular with the sun rays. It proposed the solar rays absorption of the solar panels. Two three-phase hybrid stepper motors were selected as the implementation components. And according to the problems of the low-frequency oscillation and noise, this article proposed uniform subdivision and constant torque control method, using sine wave subdivision circuit tracking pulse-width modulation to implement the subdivision control of the three-phase hybrid stepper motor. DSP(1) TMS320LF2407A were both used in dual-axis tracking unit and stepper motor control unit, and the system has achieved good control effect.In the solar power system, the output characteristic of solar cells is non-line, and it is easily interrupted by light intensity, environment temperature and load effects. Coming from the basic principles and mathematical models of the maximum power point tracking(MPPT), the article analysis the basic methods to output power of the solar cell. And proposed using the Cuk circuit to control the working voltage point of the solar system, and using the variable step-size admittance increment method started by CVT to implement the maximum power point tracking. Using DSP(2) TMS320LF2407A as the core processor to complete the calculating of MPPT, the system used the PWM wave to control the turning on and turning off of the switch of Cuk circuit, and further controlling the voltage of the main circuit. Simulation results have showed the output power and respond speed and stability of the system have been improved greatly. For example, when solar cells were obscured by clouds and sun light recovered, the process tracked the maximum power point fast, and the solar cells putout by maximum power tracking.更多还原