基于精确线性化理论的超级电容储能系统的非线性控制算法

摘要

In view of the nonlinear characteristics of super capacitors and DC-DC converters, a nonlinear control algorithm for the super capacitor energy storage system is designed. Through the analysis on working states of the circuit, the affine nonlinear model is established. The relationship between the circuit state and the duty cycle is deduced by using the exact feedback linearization theory. Furthermore, the control algorithm is designed and its stability of internal dynamics is proved. Then the control targets of charging with constant current and discharging with constant voltage are achieved. Simulation model is constructed in the Matlab/Simulink platform. The effectiveness of the control algorithm is confirmed. Then, the difference between the nonlinear control algorithm and the PI control method is compared by experimental circuit building in laboratory. Results show that, compared with the traditional PI algorithm, using nonlinear control law in the super capacitor energy storage system can significantly improve dynamic performance and ensure stability.%针对超级电容及DC-DC电路的非线性特性，设计了超级电容储能系统的非线性控制算法。通过分析电路的工作状态，建立了电路仿射非线性系统标准型，利用状态反馈精确线性化理论推导出电路状态量与占空比函数间的关系，进而设计相应控制算法，并证明了系统的内动态稳定性，实现了超级电容恒流充电与恒压放电的控制目标。在Matlab/Simulink仿真平台中搭建仿真模型，对所提控制算法进行验证，并在实验室中搭建实验电路，比较了非线性控制算法与PI算法的控制效果。结果表明，在超级电容储能系统中采用非线性控制算法相比于传统PI算法能明显提高系统的动态性能，保证系统稳定运行。