光伏并网发电模拟装置设计

【摘要】：本系统采纳单级 DC-AC+工频变压器的拓扑结构，主电路为 IR2111 驱动的半桥式逆变电路。控制电路以 ATmega16 单片机为核心，由软件生成 SPWM 波控制 DC-AC 逆变，跟踪最大功率点。系统通过反馈信号监测频率、相位，经由 A/D 采样欠压、过流信号，控制频率、相位的跟踪和欠压、过流保护。经测试，本系统的变换效率可达 74.1%。输出正弦波形失真度小（THD=1.5%），实现了同频同相的跟踪控制和欠压保护。能够改变逆变电路的输入阻抗，调节工作点，但 MPPT 的效果未如理想。【关键词】：DC-AC；SPWM；MPPT；变换效率；频率相位跟踪The design of photovoltaic grid-connected power simulator Abstract: The topology of single-stage DC-AC+ power frequency transformer is used in this system, the main circuit is half-bridge inverter circuit driven by integrated circuit IR 2111. Microcontroller ATmega16 is the core of the control circuit, and the DC-AC inverter is controlled by the SPWM wave which is generated by software to track the maximum power point.Through the frequency and phase being monitored by the feedback signal, and A/D sampling being employed by the under-voltage and over-current signal, frequency and phase tracking and under-voltage and over-current protection are controlled by the system. By testing, the conversion efficiency of this system can reach 74.1%, and the distortion of output sine-wave is small (THD=1.5%), the same frequency and phase control can be achieved, as well asthe function of under-voltage protection. The input impedance of inverter circuit can be changed to regulatethe operating point, but the effect of MPPT is unsatisfactory. Key words: DC-AC; SPWM; MPPT；conversion efficiency; frequency and phase tracking.图 1 系统框图图 2 DC-AC 主回路原理图图 3 输入电压检测电路图 4 电流检测电路图 5 滤波电路精品文档---下载后可任意编辑1 方案论证总体方案论证方案一：如图 1 所示，硬件电路由DC-AC变换器，滤...