模块化多电平交交变频电源负序补偿控制方法

为了满足高压场合的需求,研究了一种具有负序补偿功能的模块化多电平交交变频电源(MMC-VFPS)。对于负载不平衡造成电网电流存在负序分量,在MMC-VFPS电路满足高压大功率负载供电的前提下,提出了基于该电路拓扑实现负序补偿的模型预测控制方法。根据MMCVFPS电路的拓扑结构建立数学模型,得到了简化等效电路。在此基础上,采用上、下桥臂状态寻优策略的预测控制方法,利用电压排序策略并通过修正输入电流指令和环流指令既满足了负载需求又实现了负序补偿,通过仿真验证了该拓扑结构用于负序补偿和控制策略的有效性。

Negative Sequence Compensation Control Method for Modular Multilevel AC-AC Variable Frequency Power Supply

In order to meet the requirements of high-voltage situations, the modular multilevel AC-AC variable frequency power supply(MMC-VFPS)with negative sequence compensation is studied. To eliminate the negative sequence component of grid caused by load imbalance, MMC-VFPS can both compensate for the negative sequence current and supply power to the high-power load here. According to the topology of MMC-VFPS, equivalent electrical and mathematical models are developed. On the basis of this, the upper and lower bridge arm state optimization strategy of predictive control method is adopted. By using input voltage sorting strategy and amending the reference of input current and circulating current, the demand of load and negative sequence compensation are satisfied at the same time. The relationship between negative sequence compensation and circulating current is analyzed, and the feasibility of this topology to compensating negative sequence is verified by simulation.