动态电压恢复器控制策略研究

Research of Control Strategy of Dynamic Voltage Restorer

  • 摘要: 动态电压恢复器是抑制电压跌落对敏感负荷影响的有效装置。当动态电压恢复器工作在不对称电压下时,逆变器将会持续地从电源侧吸收有功功率,引发直流侧电压泵升,严重时会损坏储能及功率开关器件。针对该问题,文章提出一种复合控制策略,即采用相移控制技术来减少逆变器对有功能量的吸收,从而抑制动态电压恢复器直流电压的泵升;采用双闭环控制技术对电网电压跌落进行抑制,提高了负载的稳定性。仿真结果表明,该复合控制策略可使动态电压恢复器具有更好的负载适应性,且使直流侧电压得到很好的抑制。

     

    Abstract: Dynamic voltage restorer is a device with effective suppression of impact of voltage sag on sensitive load. When dynamic voltage restorer is working in asymmetric voltage, the inverter will continue to absorb active power from the supply side, trigger DC voltage rise, even damage energy storage and power switching devices in severe situation. For the problem, the paper proposed a composite control strategy, which uses phase shift control technology to reduce active power absorbing of the inverter, so as to suppress the rise of DC voltage of dynamic voltage restorer, and uses double closed loop control to suppress voltage sag of power grid to improve load stability. Simulation results showed that the composite control strategy allows the dynamic voltage restorer with better load adaptability, and makes the DC voltage well suppressed.

     

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