tailieunhanh - Electric Vehicles Modelling and Simulations Part 2

Tham khảo tài liệu 'electric vehicles modelling and simulations part 2', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Electrical Vehicle Design and Modeling 19 Battery charging control During the charging of the battery . both due to the regenerative braking and the grid it is very important that the maximum battery charging current and voltage not are exceeded. The maximum allowed cell charging current can be calculated from the inner and outer voltage of the battery cell . I RBat cell cha iBat cell cha max I JBat 1 cell l t l lim . . . l J 1 n t ll J 1 11 73 In Equation 73 it is insured that neither the maximum allowed voltage or current are exceeded. The battery pack consist of N at s series connected cells and N at p parallel connected strings. The total voltage and current of the battery pack can therefore be calculated as Bat Bat sV at cell iBat Bat piBat cell iBat cha max Bat piBat cell cha max. 74 75 76 During the charging of the battery the battery cell voltage Bat cell should not exceed VBat max cell V and the maximum cell charging current should not be higher than J at 1 cell 7 A Saft 2010 . In order to charge the battery as fast as possible either the maximum voltage or maximum current should be applied to the battery. The requested battery charging current . the output current of the boost converter iBc is therefore - i iBC iBat cha max which means that the requested output power of the boost converter is pBC Bat bC- 77 78 The requested charging current insures that neither the maximum allowed voltage or current are exceeded. However for a big battery pack the required charging power might be so high that a special charging station is necessary. The requested input current of the boost converter . the rectifier current Ìrf can be calculated by Equation 31 and 78 B _ - Vth BC - Rf - J Vth BC - Rf 2 - 4RBCPbC 2RBC The grid RMS-current can therefore from Equation 34 be calculated as i. B_ . B V 3 RF V 3 RF JGrid max B JGrid max V 3 iRF JGrid max. 79 80 20 Electric Vehicles - Modelling and .