多个直流电源并联运行时,需要采用均流控制来提高运行的安全性和可靠性。在现有的诸多均流控制算法中,最大电流均流法被广泛采用,但这种均流法只能实现动态均流,致使输出电流存在低频振荡,输出电压有过电压现象。针对最大电流均流法的缺点而提出的双均流母线均流法,在硬件结构上具有2条独特的均流母线,其上分别为最大输出电流信号和最大输出电流差信号,参与均流控制的每一个直流电源以这2个均流信号为依据,可形成中间电流均流法、最小电流均流法等几种不同的控制策略。仿真分析和实验验证表明,最小电流均流法的均流效果与最大电流均流法类似;而中间电流均流法却可以实现稳态的均流控制,从根本上消除最大电流均流法在均流过程中的电流低频振荡和过电压等问题,进而在确保各个电源安全运行的前提下,提高了供电品质。
When multiple DC powers operate in parallel, it is necessary to adopt the current-sharing control for im-proving the operational security and reliability. In many existing current-sharing control algorithms, the maximum current-sharing method is widely used because of its simple circuit, good current-sharing effect and reliable opera-tion. However, the maximum current-sharing method can only realize the dynamic current-sharing control, which results in the low frequency oscillation in the output current and the overvoltage in the output voltage. In order to o-vercome these shortcomings of the maximum current-sharing method, the dual current-sharing bus method is pro-posed. There are two parts of the unique current-sharing bus′ hardware architecture, which can present the maxi-mum output current signal and the maximum output current difference signal, respectively. Each DC power supply participating in the current-sharing control takes these two signals as the basis, so as to form the intermediate cur-rent-sharing method, the minimum current-sharing method and several other different control strategies. The simula-tion analysis and experimental verification show that the current-sharing effect of the minimum current-sharing meth-od is similar with that of the maximum current sharing method, but the intermediate current-sharing method can re-alize steady current-sharing control, eliminate the low frequency oscillation and overvoltage fundamentally, further improving the power quality while satisfying the requirements of safety.