| Popis: |
This paper presents a conductive charger for automated guided vehicles (AGV), which is composed of a frontend rectifier with active power factor correction (APFC) and an input-series-output-parallel (ISOP) LLC resonant converter. The features include low voltage stress across power switches, reduced transformer ratio and RMS value of current of the LLC converter, and a wide output voltage range. The control strategy aims to regular the output voltage and current according to the load of battery, with the control of balanced capacitors voltage in series and shared output current in parallel simultaneously. This kind of unbalance is usually induced by the variance of devices parameters, such as the deviation between inductors. A simulation model is constructed to verify the performance of the power stage and control strategy. The results show that the presented charger can work properly to meet the charging requirements of low voltage battery powered AGVs. The calculation of the loss model shows that the efficiency of the ISOP circuit is improved compared with the traditional structure. |
