A High Performance Flying Capacitive Equalization

The traditional Flying capacitive equalization technology has high equalization efficiency,but it cannot achieve equalization between any two battery cells.Therefore,when the number of batteries increases,there is a problem of long equalization time and complicated structure leading to large energy loss.This paper proposes a balanced circuit topology using a switch matrix and a bidirectional DC-DC type linkage.By simplifying the balanced structure,the number of switches and capacitors in the circuit is reduced,combined with the advantages of the bidirectional DC-DC converter can be used bidirectionally,according to the battery The difference between the average voltage of the group and the voltage of each cell realizes the purpose of balancing any two cells in the battery pack.Through the establishment of an experimental test platform,the results show that when the number of battery packs is large,there will be a more obvious effect in the reduction of the equalization time and the reduction of circuit losses.First,analyze the causes and improvement measures of battery pack inconsistency;analyze the principle of common balancing technology and research status.Secondly,the topology and principle of the traditional Flying capacitor equalization technology are analyzed.To solve the problem that the traditional equalization circuit cannot achieve cross-cell equalization due to the large number of battery packs,a highperformance Flying capacitor equalization technology topology is proposed And principle,through the switch array,bipolar switch and bidirectional DC-DC converter can realize the balance process between any two unbalanced batteries in the battery pack.And the traditional Flying capacitor equalization technology and high-performance Flying capacitor equalization technology were compared for efficiency and energy loss.Thirdly,to design the circuit of the high-performance Flying capacitor balancing system,first of all,the battery voltage is selected as the balancing variable,and then the working principle of the balancing circuit is elaborated.Through in-depth analysis of the working state of the circuit,the parameters in the circuit are given.Design methods and calculation principles;then the hardware design of the balance control system and the software design of the balance system are introduced in detail.The hardware modules mainly include the power supply circuit,the voltage acquisition circuit and the drive circuit of the switch tube;the software includes the control process of the balance system And balance control algorithm.Finally,the high-performance Flying capacitor equalization system is tested and verified.In order to verify the high efficiency of the structure,the equalization experiments are designed for the battery pack in the static state,the charged state and the discharged state respectively.The experimental results prove the equilibrium proposed in this paper The circuit has a good effect in the working process of the battery pack;through the design and comparison of the traditional flying capacitor equalization technology and the double-layer flying capacitor equalization technology,the balanced experiment verifies that the high-performance flying capacitor equalization technology proposed in this paper is When the number of batteries is large,the balancing technique proposed in this paper will have a more obvious effect in shortening the balancing time and reducing the circuit loss.