The Research Based On The Fuzzy Control Algorithm Of Bidirectional DC-DC Converter

With the development of the whole car industry,hybrid and electric vehicles will become mainstream products.Both fuel cell and battery as a power source,the bidirectional DC-DC converter technology is to implement the function of key components.In electric vehicle energy management control system, motor can need, the bidirectional DC-DC converter based on the battery booster provide energy;When motor can feed,the DC-DC converter step-down,the motor produce excess energy to the battery charging,reach on energy recovery.For pure charge,the output of the battery voltage is not a constant, it is with the change of the battery capacity(SOC),the bidirectional DC /DC converter by controlling the stable output voltage, prolonging the life of the battery. Electric cars at run time, its condition is complex; their Motor with large range of load transformation; At the same time, the DC-DC converter itself belongs to nonlinear system; The traditional proportional-integral(PI) control technology cannot achieve a wide range of the converter system stability, also difficult to realize the optimal regulation. Therefore, to study other intelligent control strategy of bidirectional DC-DC converter plays an important significance in practical application.In this paper, the bidirectional DC-DC converter system set up transfer function model by using the state space average method, based on the traditional classical control theory, the voltage and current feedback controller is designed, the simulation verify the feasibility of its implementation. Under the condition of the theoretical analysis and simulation verification consistent, design a small power under 50 W the bidirectional DC-DC converter, on this basis, the design of 1KW of power vehicle two-way DC-DC converter, TMS320F28035 chip design proportion-product(PI) controller, using C language to write the relevant control software, and the electronic load simulation of the electric car work environment, to verify the feasibility of the implementation, adjust the parameter to meet the dynamic performance of the converter. For bidirectional DC-DC converter this nonlinear systems, with a wide range of load change, the system of the model parameters are also follow changes. PI controller is always difficult to achieve stability. Fuzzy control strategy for the system as a fuzzy system, through to the system input fuzzy variable and output variable the fuzzy relationship between the control system to achieve effective regulation Its advantage is that don’t need to learn the relationship between internal system, only need to master the system under the condition of control laws Therefore, this article try to use fuzzy controller to realize the two-way DC- DC closed-loop controlFinally, based on the above theoretical study and simulation experiment, and practical for the purpose to realize two-way DC-DC converter design.