光伏发电系统Boost电路采用同步技术研究

Research on the synchronization technology adopted in the Boost circuit of photovoltaic generation system

光伏发电系统受光照、温度等环境因素影响,输出功率具有随机波动性。同时光伏电池板输出电压较低,较多使用Boost电路来提高和稳定电压,以及在Boost电路上实现最大功率跟踪,充分利用光伏发电。Boost电路电压增益在电感电流连续模式下计算简便且效率更高,这导致在光伏电池电流较小时就需要较大的电感值才能保证电路处于电感电流连续模式,从而引起电感元件体积和成本增加的问题。在Boost电路中采用同步控制技术,即首先使用场效应开关管来替代原电路中的二极管,然后采用带死区控制的最大功率追踪方法,实现光伏电池电流较小时,即使采用较小电感值,也能获得较高的控制性能和转换效率。MATLAB仿真证明了该方案的可行性与有效性。

Influenced by environmental factors such as light and temperature,the output power of photovoltaic power generation system has stochastic volatility. Meanwhile,as photovoltaic panel output voltage is low,boost circuits are more used to improve and stabilize the voltage and to achieve the maximum power point tracking,which could fully use photovoltaic power generation. The calculation of voltage gain of boost converter is more efficient,simple and convenient in continuous current mode（ CCM）. But it requires larger inductance value to maintain the continuous current mode when the output of photovoltaic cells is lower,which will increase the size and cost of components. In this paper,the diode in boost converter is replaced by field-effect transistor,then the maximum power tracking method with a dead zone is used to obtain a high control performance and transfer efficiency when the current of the PV cell is low and the inductance value is small. MATLAB simulations prove the feasibility and the validity of proposed control method.