公开(公告)号：US09595864B2

公开(公告)日：2017-03-14

申请号：US14478140

申请日：2014-09-05

Applicant: ABB Oy

Inventor： Samuli Heikkilä

IPC: H02M7/487 ,  H02M1/44

CPC classification number: H02M1/44 ,  H02M7/487

Abstract: A method is provided for balancing voltages of a DC link of a multi-level inverter, where the DC link is divided into two halves by a neutral point connection. The method includes injecting a periodic common-mode voltage injection signal to a common-mode voltage reference and a periodic power injection signal to a power reference of the inverter. The power injection signal has the same frequency as the common-mode voltage injection signal. A phase shift between the common-mode voltage injection signal and the power injection signal is constant. The amplitude of at least one of the common-mode voltage injection signal and the power injection signal is controlled on the basis of a difference between voltages over the two halves of the DC link. An apparatus is also provided for implementing the method.

Abstract translation: 提供一种用于平衡多电平逆变器的DC链路的电压的方法，其中DC链路通过中性点连接被分成两半。 该方法包括将共模电压基准的周期性共模电压注入信号和周期性功率注入信号注入到逆变器的功率基准。 功率注入信号具有与共模电压注入信号相同的频率。 共模电压注入信号和功率注入信号之间的相移是恒定的。 基于DC链路两半的电压之间的差异来控制共模电压注入信号和功率注入信号中的至少一个的振幅。 还提供了一种用于实现该方法的装置。