车用发电机的节能与多电压问题研究

　　车用发电机的节能与多电压问题研究
　　Internal-combustion engine in which fuel is burned within the cylinder can transform the heat energy into the mechanical energy by the gas took the actuating medium. A transform job cycle includes air admission, compression, acting and exhausts four processes. The experiment indicated that only 20%-45% heat energy the fuel burns out in the engine transforms as the useful work, other heat energy discharges from the engine along with the cooling medium, the waste gas and so on. The energy loss also includes the internal transmission process loss that include the friction loss of the moving parts, the actuation loss of affiliated organization (timing mechanism, ventilator, water pump, oil pump, generator and so on) and loss for pumping waste gas. According to Neodymium Magnets present trend of automobile industry and energy consumption standard, energy reserves in earth only can support 50 years, therefore engine’s energy efficiency is a key issue which the current automobile industry faces in the world. As engine’s main appendage, the generator consumes engine’s output. In other words, it is an important step for the engine energy conservation to research on generator’s energy conservation.Aim at above problem, the energy conservation and the multi-voltage question with the generator are explored in the thesis. In order to enhance the power supply efficiency and avoid fierce impact which the electrical power system comprehensive promotion impose on the electrical system, the thesis regulate the generator to export the 14V/42V two kind of voltages, but the accumulator cell still exports the traditional 12V voltage. 12V accumulator cells are used to provide energy for starter, firing system when the automobile starts, 14V of generator is used for some traditional electrical device and charging for accumulator cell in time, but 42V are used for some high-power electrical equipment.
　　In order to enhance efficiency, the generator also needs to add the heat dissipating arrangement, improve transmission device like belt pulley and uses the high-speed bearing and so on.The permanent-magnet generator needn’t the external energy to http://www.999magnet.com/products/110-sintered-neodymium-magnets maintain its magnetic field after it is completed, but also bring about controlling its magnetic field is extremely difficult from outside. Which caused the application for permanent-magnet generator to receive the enormous limit, this question appears the especially outstanding to the permanent-magnet generator for vehicle. Because the generator for vehicle changes rotational speed in the very wide range, it is expected to work normally under 1000-10000r/min even wider rotational speed scope. At same time the variation of load also imposes on output voltage of the generator. How realizes constant output voltage of the generator under the situation of width rotational speed scope and variation of load, is a key issue whether the permanent-magnet generator for vehicle can work perfectly in practice.The basic method of voltage adjust in this thesis is three -phase half-wave controlled bridge rectifier circuit be controlled single-Chip Microcomputer, the generator to output the 14V/42V two kind of voltages. Three thyristors of three -phase half-wave controlled bridge rectifier circuit be controlled single-Chip Microcomputer, it is according to basis circuit, sample examination circuit, comparison http://www.999magnet.com/products/110-sintered-neodymium-magnets circuit and protection circuit to control flip-flop circuit.Based on the study , this design decides to use the power 1.5 kW PM generator that is ensure to work within the speed range of 1000 - 10000 r/min and export 14 V and 42 V two kinds of constant direct current voltage. It can fulfil the demand of a most part of using electricity equipments and additional 42V using electricity equipments in current cars, so it is worthy of a certain popularization.