Design Of Bidirectional DC/DC Converter For Super Capacitance Based On Independent Pitch Wind Power Generation System

With the exhaustion of traditional fossil energy,wind energy has been widely used as a kind of new energy.The wind power generation system with independent pitch system can make use of wind energy effectively and increase the generating capacity of the system.The back-up power supply plays an important role in the pitch system,comparing various energy storage technology and the working characteristics of the reserve power supply of the pitch system,the super capacitor can improve the service life of the system and enhance the reliability of the pitch system,in order to improve the performance of back-up power supply,bidirectional DC/ DC converters are introduced into the Super Capacitor energy storage System.In this paper,the topology deduction based on the traditional bi-directional converter is introduced,and a new type of staggered-parallel bidirectional DC/DC converter is proposed,and a reasonable control method is put forward for the two working modes,the specific research contents are as follows:(1)The development of wind power generation history,as well as the current situation at home and abroad are briefly introduced,and then the existing energy storage technology and future development potential to do a simple introduction of the Super Capacitor and DC/DC converter working principle and characteristics of various applications.(2)In view of the particularity of the reserve power supply of the pitch system,a new bidirectional DC/DC converter with high voltage gain and low voltage stress is selected,and the working principle of the two working modes is expounded,and compared with the traditional staggered parallel bidirectional DC/DC converter.The comparison results show that the new converter is very suitable for the super Capacitor energy storage system,and it can be used in the reserve power system of the pitch system,so that the reliability of the pitch system is enhanced and the operation efficiency is improved.(3)First,the small signal model is established for the two working modes of the new converter,and their respective controllers are designed.Aiming at the current error of phase shift control,a reasonable explanation is put forward and improved,and a double current inner loop control strategy is proposed.The simulation results show that the super capacitor can charge rapidly when the converter works in Buckmode under the improved strategy.When the converter works in Boost mode,the super capacitor is the input power supply,which can rapidly and steadily discharge deeply and output electricity.The voltage is stable at the rated value in a short period of time,and when the input voltage and load power change suddenly,the output voltage of the high voltage side can recover to the steady state after a short period of fluctuation.It shows that the improved control strategy not only improves the dynamic response speed of the system,but also improves the anti-jamming performance of the system.