Study Of Reversible PWM Rectifier And Its Control Strategy

Battery formation manufacturing process is a key process, which directly affects the battery's quality and production costs. At present, the technique of single cell discharging is used in the battery formation, causing a lot of wasted energy, which in the current battery of large capacity and production trend of rapid increase is particularly serious.As PWM rectifier can realize bi-directional transfer of its energy and high power factor connecting to the grid, so it has also been applied to the battery charge and discharge technique. To achieve high efficiency, the new battery formation system needs a way to charge and discharge modules provide more energy, but also to their overall charge and discharge the excess energy of the bi-directional converter feedback the grid. This paper designs and develops a highly efficient single phase reversible PWM rectifier, which based on DSP56F803 control. Through analysis and comparison of different PWM rectifier control scheme, the classical digital PI control combined with tracking difference of current control is presented and this paper also analysis the reason of current distortion near the peak when the voltage of DC bus close to grid voltage and put forward to adjust measurement points and compensate the duty as improved method. The design contains the main circuit parameters of the rectifier, drive circuit, measuring circuit and other hardware, and a full software program. Produced prototype completed the state's test and a joint debugging with the whole battery formation system. The results showed that efficiency of PWM rectifier up to 94%,98% power factor, harmonics are limited to 5% in the half load or full load. It satisfies design requirements and validates the feasibility of the control strategy and the overall scheme.