三相多驱动系统带移相电流控制的谐波消除方法

Harmonic elimination method with phase-shifted current control in a three-phase multi-drive system

目前,许多三相可调速驱动器仍采用二极管整流器(DR)或半可控硅整流器(SCR)作为前端整流。但是,这种AC-DC整流会带来大量谐波电流,使电网电流畸变。现有的谐波消除策略因为总成本高和复杂性难以运用到多驱动系统中。因此,提出了移相电流控制和直流调制相结合的新方法来减轻多驱动系统中谐波电流。并且分析了并联驱动器之间不相等负载的影响,运用负载自适应方案确保各个整流器从电网汲取的电流幅值相等,从而增强了移相电流控制谐波消除效果。仿真和实验结果证明了该方案在三相多驱动系统中谐波消除的有效性。

At present,many three-phase adjustable speed drives still use a Diode Rectifier(DR)or a Semi-Controllable Rectifier(SCR)as the front-end rectifier.However,an AC-DC rectifier will bring a lot of harmonic currents and distort the grid current.The existing harmonic elimination strategy is difficult to apply to multi-drive systems because of its total cost and complexity.This paper proposes a new method combining phase-shift current control and DC modulation to mitigate harmonic currents in multi-drive systems,and the influence of unequal loads among parallel drivers is analyzed.The load adaptive scheme is used to ensure that the amplitude of the current drawn from the grid by each rectifier is equal,thereby enhancing the harmonic elimination effect of the phase shift current control.Simulation and experimental results prove the effectiveness of this scheme in harmonic elimination in a three-phase multi-drive system.