ACTIVE BALANCING OF VALVE-REGULATED LEAD-ACID BATTERIES IN ELECTRIC VEHICLES

Abstract

The article deals with questions of operation connected in batteries in electric vehicles. Pro- longed excess or under-voltage on the battery terminals to their limits leads to premature destruction of the chemical structure. Control only total battery voltage leads to destruction of the effect of a weak battery. When using batteries based on lead the process of destruction is almost imperceptible at first, but then de- velops an avalanche. The authors suggest the use of an active balancing battery. The level of the required balancing current is determined by two factors: advantageous discharge and recharge currents and capaci- tance unbalance batteries. To assess the necessary balancing currents at different driving styles were meas- ured. Significant differences of currents consumption probabilities when traffic on the settlements in econo- my mode; at uniform movement out of the municipality; when driving on the settlements in the "taxi" mode. Dana stats residual capacity of the battery after use in electric vehicles. balancing scheme was proposed, in which the flow of power is only between adjacent batteries. A feature of the balancing system is that if a bat- tery with a minimum and maximum capacitances are not adjacent to each other, the pumping energy accu- mulators produced by the chain between them. We investigated changes in battery voltage without balancing and active balancing. Maximum battery imbalance appears at the end of charging when entering the con- stant voltage mode. It was revealed that the balancing of lead-acid batteries in electric car is only necessary in the ranges below and above 11,8V 14,5V. Maximum voltage unbalance with the active balancing is turned on decreases in 1,5 times. It raises the minimum voltage at peak loads. Total mileage electric car when the rocker has increased significantly.