针对链式静止同步补偿器中直流电容电压平衡的问题，在分层控制架构的基础上，提出基于有功电压矢量叠加的平衡控制方法。上层通过解耦控制完成三相链接总的有功和无功控制；下层采用所提出的平衡控制，在上层输出的控制量上叠加一个与输出电流方向平行的有功电压矢量对同相链节间的有功进行分配，实现直流电容电压平衡控制。对直流电容电压平衡控制进行矢量分析，得到其稳定工作区域以及所提控制方法的物理意义和调控范围。研制了一台三相36个链节的物理样机，并在样机上进行了实验验证，证明了所提控制方法的有效性和可行性。

In order to balance DC capacitor voltage of cascade multilevel static synchronous compensator (STATCOM), a novel method was proposed based on active power voltage vector superposition in hierarchical control structure. Decoupling control method was adopted to realize both active and reactive power control in the upper layer. The proposed balancing control was applied in the lower layer through adding an active power voltage vector paralleling with output current to the upper output control vector, so active power among homophase chains could be distributed and DC capacitor voltage balance could be achieved. Steady state operation area and operation region of the proposed control method were also analyzed. A prototype of three-phase 36-chain STATCOM had been developed to verify the theory analysis.

国家重点基础研究发展计划项目(973项目)(2009CB219701)。