The Research Of Intelligent Charge Technology Of Storage Battery Based On VRLA Of Fuzzy Logic Control

Nowadays, VRLA storage battery becomes the most widely and maturely one of all the secondary batteries. Due to the VRLA storage battery has the advantages of high electromotive force, regular voltage, discharge with big current, low price and so on, it is used widely in various national economy domains especially in the power train power supply, factory and mine electric locomotives power supply, the auto start power supply and so on. The VRLA storage battery has the status which cannot be substituted relative to other storage battery.But as a result of the limitation of engineering factor, we often use the regular charging method such as constant voltage, constant voltage with current limitation and constant current. These charging methods has not been able to comply with the internal physical and chemistry rule of battery, most of them has serious phenomenon of surcharge and Outgoing gas ,at the same time, they can make the charging process has the disadvantages of low efficiency, long charging time and easy to damage the storage battery . Therefore, a new charging technology which both can enhance the energy use efficiency and speed up the charge speed as well as does not affect the VRLA storage battery's service life becomes the concerned and rapid development realm of the electric power electronic technology and the automatic control technology.Recent years, many experts and scholars in domestic and overseas have studied the mathematical model of storage battery and have some achievement, such as four-stage dynamic circuit model. For the reason that the charging process is affected by complicated storage battery parameter, these parameters in the mathematical model are dynamic and changeable. It is hard to use it in daily intelligent charging area. Even though many researchers try to use it, none of them get satisfied achievement continuously. In the three aspects of high-efficiency, fast and damage-free, presently, domestic and overseas generally accept a quite goodcharging way is to cause its charging current to track as far as possible the American scientist MAS (J.A.MAS) who proposes the charging current curve which may accept by the storage battery and is based on the lowest out-gassing rate. This curve is the optimum charging curve. However, as a result of complexity and non-linearity of storage battery technology condition, the fundamental research and the technical development along with this direction still is at the initial stage and has suitable difficulty.For this reason, this dissertation has studied each kind of conventional charge pattern according to the charging character of storage battery and put forward the intelligent charging method on the basis of fuzzy logic control. This method casts away the study of storage battery model. According to technical personnel's knowledge and experience, in the situation when we don't know or knew limitedly characteristic parameter of storage battery, we decide the size of charging current on the basis of the size of some several inputs or feedback value in battery charging-up process. Thus we can achieve the changing process of high-efficiency and damage-free.The author has analyzed some correlation questions, such as the selection of fuzzy variable, the determination of fuzzy rule, the realization of fuzzy logic control algorithm and so from the fuzzy control angle, and in detail introduces the design process of fuzzy controller of intelligent charging, including the selection of input value and output, the division and expression of fuzzy quantity, the establishment of control rule and so on. The charging current can carry on the change under the fuzzy logic control charging mode according to the charge condition of storage battery, this result has realized the intelligent charging in the true sense.In the dissertation, the author has designed a set of single-phase charging test device on the bases of single chip microcomputer STC89C516RD+, it may work under fuzzy logic control charging mode and two-stage control charging mode. Because of the big workload, meanwhile, in order to speed up the experimental progress, the main circuit has not used the three-phase fully-controlled bridge type rectifying circuit, but single phase fully-controlled bridge type rectifying circuit to replace, focusing on the charging effect. At the same time, the author has designed the charging device software, including the software realization of fuzzy control algorithm, the software realization of constant current charging as well as thecontrol software of entire charging device and so on.Under the two control modes: fuzzy logic control charging mode and two-stage control charging mode, the author has done a charging experiment and compared with their charging effect. The analysis of the experiment data shows the advantage of fuzzy logic control charging mode. This result has confirmed the correlation theories and yielded certain result to the fuzzy control research of the charging current.Finally, the author analyzes the question which is discovered in the experiment, and put forward the proposal for the further research in the future days.