一种光伏系统的整体线性化模型

A Global Linearization Model for Photovoltaic Systems

为解决光伏系统的非线性特性问题,对光伏系统进行控制策略设计和优化,提出一种光伏系统整体线性化建模方法。首先,根据光伏系统中各组件的工作模式以及工作状态,通过状态空间平均法建立空间状态方程,推导出各部件的线性状态数学模型。接着,将各部件的数学模型相结合,得到光伏系统的整体线性化数学模型。然后,通过Routh逼近法对整体线性化模型进行降阶处理,获得简化光伏系统整体线性化模型。最后,利用Matlab/Simulink仿真平台获取仿真结果。结果表明,光伏系统整体线性化模型具有可行性和实用性;当辐照度变化时,系统的输出电压在辐照度变化点均能在0.02 s内恢复稳态,具有一定的调节能力、准确性及抗干扰性;光伏电池模型输出与实际输出的误差小于5%。该方法可为经典控制理论对光伏系统的线性控制及优化提供理论基础和参考价值。

To solve the problem of nonlinear characteristics of the photovoltaic system and to design and optimize the control strategy of the photovoltaic system,a linear modeling method for the photovoltaic system was proposed.Firstly,according to the working mode and working state of each component in the photovoltaic system,the spatial state equation was established through the state space average method,and the linear state mathematical model of each component was derived.Secondly,the mathematical model of each component was combined to obtain the overall linear mathematical model of the photovoltaic system.Thirdly,the overall linearization model was reduced by the Routh approximation method,and a simplified overall linearization model of the photovoltaic system was obtained.Finally,the Matlab/Simulink simulation platform was used to obtain the simulation results.The results showed that the linearization mathematical model confirmed the feasibility and practicability of the proposed overall linearization model of the photovoltaic system.When the irradiance changed,the output voltage of the system returned to steady state within 0.02 s at the irradiance change point,which had some adjustment ability,accuracy and anti-interference.The error between the photovoltaic cell model output and the actual output was less than 5%.The proposed method provided a theoretical basis and reference value for classical control theory to linear control and optimization of photovoltaic systems.