公开(公告)号：US20160139578A1

公开(公告)日：2016-05-19

申请号：US14897116

申请日：2013-06-12

Applicant: ABB TECHNOLOGY LTD

Inventor： Jean-Philippe HASLER ,  Jan KHEIR

IPC: G05B19/042 ,  G05B19/10 ,  H02J3/18

CPC classification number: G05B19/042 ,  G05B19/106 ,  G05B2219/2639 ,  H02J3/18 ,  H02J3/1857 ,  H02M2007/4835 ,  Y02E40/26

Abstract: The invention relates to methods and devices for controlling unbalanced active power flow in a three-phase modular multilevel converter 20. The converter 20 comprises a first and second converter 4, 5 both comprising three phase legs arranged in a wye-connection. The first and second converters 4, 5 are interconnected in a double-wye connection, and their neutral paths are independently floating. The method 200 comprises: detecting an active power flow in the phase legs; determining a zero-sequence voltage, the determination providing magnitude and phase of the zero-sequence voltage; re-computing the magnitude of the zero-sequence voltage while keeping the phase of the zero-sequence voltage fixed, the magnitude being re-computed with the requirement that the resulting voltage over the phase legs is smaller than or equal to a maximum allowed leg voltage, the re-computed magnitude and the phase giving a re-computed zero-sequence voltage; imposing the re-computed zero-sequence voltage on the neutral point of the first and second converters, thereby reducing the active power flow determining remaining active power based on the re-computed magnitude of the zero-sequence voltage; determining a DC current giving a product with a DC voltage of the first and second converters 4, 5 that will counteract remaining active power; and imposing the DC current on the phase legs.

Abstract translation: 本发明涉及用于控制三相模块化多电平转换器20中的不平衡有功功率流的方法和装置。转换器20包括一个第一和第二转换器4,5，它们都包括以三角形连接布置的三相支路。 第一和第二转换器4,5以双重双向连接互连，并且其中性路径独立地浮置。 方法200包括：检测相腿中的有功功率流; 确定零序电压，所述确定提供零序电压的幅度和相位; 重新计算零序电压的幅度，同时保持零序电压的相位固定，该幅值被重新计算，要求相位支路上产生的电压小于或等于最大允许支路 电压，重新计算的幅度和给出重新计算的零序电压的相位; 在所述第一和第二转换器的中性点上施加重新计算的零序电压，从而基于所述零序电压的重新计算的幅度来减少确定剩余有功功率的有功功率流; 确定产生具有将抵消剩余有功功率的第一和第二转换器4,5的直流电压的产品的直流电流; 并在相位腿施加直流电流。