基于模糊PID的Z源逆变器直流链升压电路控制

提出一种模糊PID补偿器用以直接控制Z源逆变器直流链电压最大值。控制至直流链电压最大值传递函数有一左(左半平面)一右(右半平面) 2个零点，同时零、极点位置相近且靠近虚轴，具有严重的非最小相位现象。该文在详细的分析了控制至直流链电压最大值传递函数的基础上，针对Z源逆变器应用场合(燃料电池或光伏发电)中，输入电压大范围波动的特点，设计了具有良好非线性控制性能的模糊PID控制器。应用相平面响应轨迹特征向量法修正了模糊规则库，使系统具有良好的动态响应，同时用相平面法对闭环控制器进行了稳定性分析。该控制器能够实现直流链电压最大值的直接控制，消除了2个靠近极点的零点(1个右半平面和1个左半平面)造成的影响。减少了非最小相位系统阶跃响应的超调和负调。控制器设计简单，鲁棒性好，对输入电压扰动和负载电流变化具有良好的抗扰能力，动态、静态性能有了明显的改善。通过仿真和实验结果验证了理论分析的正确性。

Fuzzy PID Controller for DC-link Boost Voltage in Z-source Inverter

A direct peak DC-link Boost voltage fuzzy PID controller in Z-source inverter is proposed. With this technique a constant peak DC-link voltage can be achieved with an excellent transient performance which enhances the rejection of disturbance, including the input voltage and load current variation, and solves the problem of the local dynamic output feedback stabilization of the serious non-minimum phase system, simplifies the controller design. The small signal model of the Z-source network and non-minimum phase phenomenon of the control-to-output voltage transfer functions have been discussed in detail. The two zeros (a LHP zero and a RHP zero) of the control-to-peak DC-link voltage transfer function increasing the controller design difficult. A phase plane is presented to describe the control effort transient response, analyze system stability, and modify the rule matrices of fuzzy controller. The proposed technique was verified on a 10 kW prototype. The experimental results meet the simulation and analysis results very well.