Electric Bus Capacitors Battery Module Research

With the fast development of new energy electric vehicles, now traditional lead-acid battery has serious pollution problems, such as short life and pollution problems. now, people use Ni-MH power battery in the pure electric vehicles, according to the operating characteristics of electric bus proposed corresponding fast charging method. The innovation of this paper is that how to balance small current fast charging, cooling medium and gas equalizing. The gas equilibrium is special, battery compartments have different pressure values during the battery reaction and it causes battery cell electrical performance different in each battery cell interior, it can reduce inconsistencies by the gas equilibrium.This paper combines my tutor who chair the project of the 863 major projects, the project is “high-performance Ni-MH power battery and electric vehicle assessment”. Combining with Zibo MH/Ni power battery electric bus project, and according to the characteristics of pure electric bus’ s operation in the city and the features of Ni-MH power battery charging, we design planning of the pure electric bus charging operation mode, which named balanced slow charging at night and day 3-4 times quick supplementary charging. According to the analysis in the process of Ni-MH power battery charging gas and composite features, small current sawtooth equalization charging method is proposed. This article main research content is as follows:1. Introduces the equilibrium solution of general classification, and analyzes the common several kinds of balancing solution and their existing problems.2. This paper analyzes the working principle of Ni-MH power battery and its electrical characteristics, according to the analysis in the process of Ni-MH power battery charging gas and composite features, and it provide theoretical foundation for sawtooth equilibrium charging method.3. Analyzed the series of Ni-MH battery power battery equalization method and principle. This article focuses on sawtooth equilibrium principle and equilibrium charging system’s hardware design, according to protection scheme and the modular design thinking, analyzes in detail the system main circuit module, control module, protection circuit module and the main detection module and design the circuit.4. The charge equalization main circuit module adopts three-phase twofold 12 pulse rectifier circuit as the main circuit; Control circuit adopts the way of digital phase shift trigger circuit; Protection circuit include the phase sequence protection of main circuit, over-voltage and over pressure protection of battery pack; Detection module include current detection,voltage detection and temperature detection, real-time monitoring of dynamics of battery pack ensure the safety in the process of charge and discharge.5. Finally for electric buses for field test. In this paper, design of Ni-MH power battery equalization system can achieve very good charge equalization effect by experiment, equilibrium charging system is helpful to extend the service life of the battery and increase the range of the electric bus.