IGBT并联应用的均流探讨

Discussion on Current Sharing in Parallel Application of IGBT

IGBT是经济实惠的半导体器件,其具备低导通压降与高输入抗阻的特性,可以在牵引传动、开关电源、交流电机、照明电路、变频器等变流系统以及600V的直流电压中被广泛应用。通常会使用IGBT并联的方式达到所需要的功率标准,但是同时也会面临电流不均衡的问题。通常出现电流不均衡的因素是IGBT自身特性、驱动电路与外围主电路。对于动态电流不均衡在关闭时主要对其会造成较大影响的因素是IGBT自身特性的结温、驱动电流的输出阻抗、驱动电流的栅极连线、外围主电流的主流母线侧;在开通时主要对其会造成较大影响的因素是IGBT自身特性的结温、输出阻抗、栅极连线,主流母线侧对均流的影响较小;对于稳态电流不均衡在负载电流变化较快时,只有外围主电路的负载侧对均流有大的影响;当负载电流变化较慢时,IGBT自身特性的结温与饱和压降对均流的影响大。通过选择同一厂家与批次的器件以及调整电路结构,可以解决IGBT并联的均流问题。

IGBT is an economical semiconductor device with low on-voltage drop and high input resistance.It can be used in converter systems,switching power supplies,AC motors,lighting circuits,inverters and other converter systems, as well as 600V DC voltage.widely used.Usually,the IGBT is connected in parallel to achieve the required power standard, but at the same time,it will face the problem of current imbalance,which usually leads to the current imbalance,the IGBT's own characteristics,the drive circuit and the peripheral main circuit.For the dynamic current imbalance,it will mainly have a large impact on the IGBT's own characteristic junction temperature,the output impedance of the drive current,the gate line of the drive current,and the mainstream bus side of the peripheral current.Mainly it will have a large impact on the junction temperature,output impedance,and shed connection of the IGBT's own characteristics.The mainstream bus side has less influence on the current sharing;for the steady-state current imbalance,when the load current changes rapidly,Only the load side of the peripheral main circuit has a large influence on the current sharing;when the load current changes slowly,the junction temperature and saturation voltage drop of the IGBT's own characteristics have a great influence on the current sharin g. By selecting the same manufacturer and batch of devices and adjusting the circuit structure,the current sharing problem of IGBT parallel can be solved.