PID controllers are widely used in industrial process control. The determination of the conventional PID controller parameter tuning is based on obtaining the mathematical model of controlled objects and according to certain rules, which is difficult to adapt to complex control systems. In this paper ,against its adverse effect parameter tuning, long time debugging, defects and poor adaptability of the controlled object,the fuzzy control and PID control are combined and the fuzzy PID controller is proposed. Then, I combine the examples of thermal power units using MATLAB to simulate. The simulation results show that the fuzzy self-tuning PID controller not only has the advantages of fuzzy control such as fast, adaptability, etc, but also the characteristics of high accuracy PID control, which make the system has a good control effect.

Due to the large number of distributed power supply random connected to power grid, it has severely influenced on power quality of the grid. In the storage battery directly on the basis of the DC bus, adopting the method of hybrid energy storage system makes a research on the output characteristics of photovoltaic array and the charging and discharging of battery and super capacitor. Research results show that the hybrid energy storage system can take advantage of the DC/DC converter to coordinate photovoltaic array, energy storage unit and the energy flows among load, also that the stability of DC bus voltage can be ensured by the system switch from the different work patterns.