Fuel battery automobile mixed power system using super capacity as auxiliary power device

Abstract

The fuel cell vehicle mixed power system using super capacitor as auxiliary power device belongs to the field of fuel cell vehicle technology. The galvanic pile of fuel cell system is connected with motor controller by means of forward direction of power diode: the super capacitor is connected with cathode of power diode by means of bidirectional main DC / DC converter; the low-voltage end of bidirectional 24V DC / DC converter is connected with 24V battery, its high-voltage end is connected with cathode of power diode; the motor controller, bidirectional main DC / DC converter, super capacitor management system, bidirectional 24V DC / DC converter, fuel cell controller and whole vehicle controller are electrically connected; and the fuel cell controller, bidirectional main DC / DC converter, bidirectional 24V DC / DC converter, motor controller and super capacitor management system are connected with whole vehicle controller by means of CAN network.

Description

technical field [0001] The invention relates to a hybrid power system of a fuel cell vehicle in which a supercapacitor is used as an auxiliary power device, and belongs to the field of fuel cell vehicle research and development. Background technique [0002] The widespread use of traditional internal combustion engine vehicles powered by fossil fuels such as gasoline or diesel is an important reason for the shortage of energy supply and serious environmental pollution in the world today. Fuel cell vehicles are widely considered to be the development trend of the future automobile industry due to their excellent performances such as quietness, high efficiency and zero emission. In the face of the sharp contradiction between energy and environmental issues and the development of the automobile industry, the national "Tenth Five-Year Plan" 863 major special project for electric vehicles has set up sub-projects for fuel cell cars and fuel cell city buses, and the research and de...

AI Technical Summary

Problems solved by technology

But such a fuel cell vehicle hybrid power system also has the following problems: First, after the fuel cell system starts to work, the power supply of the fuel cell auxiliary subsystem seems to be provided by the battery pack, but in fact, the fuel cell auxiliary subsystem The power supply of the system is actually undertaken by the fuel cell system itself, because during the whole process of fuel cell vehicle operation, under normal circumstances, the battery pack is not additionally charged, and the energy replenishment of the battery pack is the same as its energy release. It is all completed during the working process of the vehicle power system, and the electric energy storage of the battery pack comes from the fuel cell system.

As a result, the above-mentioned power system structure has the following problem: the electric energy required by the fuel cell auxiliary equipment actually flows out from the fuel cell system (fuel cell stack), and after passing through the unidirectional DC / DC converter, reflow back to the fuel cell system (fuel cell auxiliary equipment)

On the one hand, this energy flow will lose part of the energy when it passes through the DC / DC converter (for example, for a 100kW fuel cell, the power required by its auxiliary equipment is usually between 10 and 20kW, and the efficiency of the DC / DC converter is generally between 96%, then in such a system, only 800W of power will be lost in the power supply of fuel cell auxiliary equipment); secondly, when the car is running at a constant speed, all the required power should be provided by the fuel cell system, because DC / DC converter, at this time, nearly 4% of the output power of the fuel cell system is wasted, thereby reducing the efficiency of the entire power system; third, because the output power of the DC / DC converter is close to that of the fuel cell The output power of the system and the power capacity of the DC / DC converter must be very large, resulting in a much larger volume, weight and cost; fourth, in this fuel cell vehicle hybrid system structure, Due to the low charge and discharge efficiency of the battery pack (about 85%) and low service life (thousands of cycles), the efficiency and service life of the entire fuel cell vehicle power system are affected

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