中压直流换流站最优电流控制算法研究

Optimal Current Control Algorithm in Medium Voltage DC Converters

在中压直流换流站双闭环控制的电流内环层面,适当的控制策略有助于换流站在电压调节和紧急功率支援等方面发挥作用。以换流站数学模型为基础,首先回顾了传统PI电流控制方式的特点。然后基于极小值原理推导了最优电流控制条件。进一步,分析了将这些条件直接用于实时控制时所遇到的困难并给出了解决方案,由此得到了满足实时运算要求的滑模最优电流控制算法,该算法可以提升电流控制的响应速率及系统的动态稳定性。最后将该算法与传统电流控制算法进行了动态模型对比仿真,得到了预期的结果。

On the current inner loop level of a medium voltage DC converter double-loop control,an appropriate control strategy helps the DC converter play an important role in situations as voltage regulation,emergent power support,and so on.Based on the mathematic module of the DC converter,the properties of traditional PI current control were discussed firstly.Then the optimal current control conditions were deduced based on the minimum principle.Furthermore,the problems in real-time control utilization under these conditions were analyzed and solved,so the optimal current control algorithm with sliding mode was proposed to benefit current control response speed and system dynamic stability.Finally,the devised optimal control was paralleled with the traditional current control with dynamic module simulation software,expected results obtained.