Vehicle-mounted composite power supply system of electric vehicle and control method

Abstract

The invention discloses a vehicle-mounted composite power supply system of an electric vehicle and a control method. Through a voltage and current acquisition circuit, a voltage value and a current value of a motor inverter end, and voltage values of a battery set and a supercapacitor are obtained, and the processed to obtain required power, battery set SOC and supercapacitor SOC, which are used as decision-making input variables of a fuzzy logic control module. According to actual operation working conditions of the electric vehicle, a proper logic threshold value control strategy is formulated and by use of fuzzy control, fuzzification is performed on fixed rule parameters in a logic threshold, so rules are further refined, control thinking is further precise and results are further optimized. Compared with real-time power, the peak value of actual average power and the switching frequency are greatly reduced. By combining the power hysteresis control, the switching frequency of working modes of the system and the output frequency of the battery set are further improved, energy loss, caused by mode switching, of a vehicle-mounted double-energy system is reduced, service lifetime of the battery set is prolonged and efficiency and stability of the system are improved.

Description

【Technical field】 [0001] The invention belongs to the field of vehicle-mounted composite power supplies of electric vehicles, and relates to a vehicle-mounted composite power supply system and a control method of electric vehicles. 【Background technique】 [0002] The energy management strategy of the vehicle composite power supply is one of the hot research topics in the electric vehicle industry. One of the difficulties is that the composite power supply system has many operating modes and often jumps. High frequency mode switching causes high switching energy loss, short component life, A series of problems such as low system efficiency and poor stability have a negative impact on the performance of the composite power system, and more seriously limit the popularization of the composite power system and electric vehicle technology, which is not conducive to energy saving, emission reduction and environmental protection. 【Content of invention】 [0003] The purpose of the ...

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Problems solved by technology

[0003] The purpose of the present invention is to overcome the shortcomings of the existing composite power supply system of electric vehicles such as frequent switching of working modes, low component life, low system efficiency and instability, and provide a vehicle-mounted composite power supply system and control method for electric vehicles

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