Research On DSP-Based Charging Power Supply Of Lead-Acid Battery

The lead-acid battery that was called secondary power supply was widely used in industrial and agricultural production. The lead-acid battery that was invented ever since 100 years ago was rapidly developed. Especially the invention of the maintenance-free valve regulated lead-acid battery short as VRAL soluted the problem of acid-liquid out leakaging and maked the lead-acid battery rapid developed and widely used. From the various toys to electric vehicles, we can find the shadow of the lead-acid battery. As a secondary energy, the charging technology is a key fact that infects the battery's service life and security. However, the present widely used charging power supply behaved a badly charging curve that decreases the charging speed and efficiency. Worse lucky, some charging method curtails the lead-acid battery's service life artificially. So, adopt-ing the propose charging curve and developing a right charging power supply becomed a very important task. A high efficiency and rapid charger becomes a crying need.Traditional charging methods are usually charging with a constant voltage or con-stant current curve. However, according some correlation theory, the pulse constant voltage charging method can get an approaching ideal charging curve and it is a very good charging method. Using this charging method, the scathe of the battery caused by the charging can decrease a very low level. The key problem of realization the method is to design a power supply to satisfy the charging request. The supply should be com-mercial power inputting and the power converter part adopts the AC/DC converter. The supply not only realizes the pulse constant voltage and it should also be high efficiency, easy to realize, low cost and easy to use.Phase shift full bridge PWM converter is used in some output low voltage high power, input voltage and power variation case. The specialty of the converter is constant switch frequency, easy to control and based on phase shift control technology. Parallels a shunted capacity and appends a resonant inductor on the topology, the four switches can switching on and off with zero voltage in turns that makes it easy to realize the con-stant frequency soft switching.This paper based on the charging theory, combined with the superiority of phase-shifted full-bridge circuit on carrying a low-voltage heavy-current load, designed a high-efficiency charger. This paper designs the main circuit, selects and makes the needed power device, designs the control, drive circuit, capture circuit and the assistant power supply, and realize the soft PI modulation algorithm.To improve the DC/DC converter's stability and anti-jamming ability, this paper constitutes the small-signal model, makes the analyses of model and designs the com-pensator under the voltage control mode and which is validated using the saber simula-tion software, constructed the experimental circuit and gave the experimental waves. Based on this, finished the contrast experiment of battery charging using traditional charging method and pulse voltage charging. The result validates the feasibility of the pulse charging method.