On Semi车载充电器(OBC)LLC转换器解决方案

On Semi公司的车载充电器(OBC)包括两个不同的级:AC/DC转换器和DC/DC转换器. PFC的目标是整流由火线所提供的输入电压,保持功率因速尽可能接近一.而DC/DC转换器提供电流隔离和电池管理系统所需要的输出电压/电流.因此,DC/DC转换器是任何OBC系统的关键区块.众多所用的拓扑中,LLC转换器是最常用的一种,具有良好的效率和温和EMI指纹.另一方面,在OBC应用的通常所见的宽输出电压范围可能存在严重的设计复杂性.本文所描述的是采用On Semi公司的碳化硅MOSFETNVHL080N120SC1 (N−Channel, 1200V, 80m _, TO247−3L)和SiC MOSFET 驱动器NCP51705.车载充电器(OBC)LLC转换器主要特性是输入电压700V ±35 V,输出电压200V/450V,最大输出功率10kW,最大开关频率400kHz,具有USB和CAN总线接口的微控制器控制,采用液体冷却,不带谐振箱的板尺寸为360 × 187× 92 mm.本文介绍了车载充电器(OBC)系统架构图, 车载充电器(OBC) LLC框图,各种工作模型图,以及OBC LLC开关板电路图,材料清单和PCB设计图.

Nowadays, so called plug in hybrid as well as fully electric vehicles are catching more and more attraction triggered by the reduction of pollution as it is normally happening with pure combustion engine. Nevertheless, there is at least one feature that is common to all of them electric energy is accumulated in dedicated battery pack and it is used in electric motors afterwards. Although this technology still undergoes heavy development nowadays, so do also relevant technical standards, it is clear that charging energy is provided utilizing existing mains infrastructure. Hand in hand, it implies certain requirements put on chargers, those installed On Board as well as on those installed Off Board.

LLC Converter in OBC Applications

As can be seen also in Figure 1, a typical battery charger application consists of two different stages, AC−DC converter and DC−DC converter. PFC goal is to rectify the input voltage normally provided by a mains, keeping power factor as close as possible to unity. DC−DC converter provides galvanic isolation and the output voltage / current levels as requested by the battery man...