具有输出短路保护能力的DC-DC换流器控制方法研究

A DC-DC Converter Control Method with Output Short-circuit Protection Capability

由于经济、技术等方面的优势,直流换流器已得到了广泛的应用,并且还将进一步发展。Boost升压电路自身没有限流能力。Buck降压电路输出侧有电感存在,因此具备一定的限流能力。本文提出一种具有输出短路保护能力的DC-DC换流器控制方法,将Boost-Buck背靠背结构的换流器通过合理的控制,使其具有很好的负载短路特性。通过电压电流双闭环控制实现正常工作状态下的恒压源输出,当负载短路时,通过采样输出电感电流做闭环控制,使换流器工作于恒流源状态,使其具备短路保护能力。系统的仿真分析和实验结果证明Boost-Buck换流器利用提出的控制方法具备了良好的负载短路特性。

Due to economic,technological and other advantages,the DC converter has been widely used,and will be further developed.Boost converter is short of the ability to limit load current.Buck converter has the ability to limit short-circuit current,owing to outside inductance.The converter,consisting of Boost-Buck back-to-back structure,can limit the load short-circuit current perfectly by the control method presented in this paper.By voltage and current double closed-loop control,the converter works in the state of constant voltage source.When the loads short-circuit occurs,the converter works in the state of constant-current source by sampling the output inductor current for closed-loop control.By this control method,the converter has the ability of load short-circuit protection.System simulation and experimental results demonstrate this conclusion that with the proposed control method,the Boost-Buck converter has a good load short-circuit characteristics.