基于复功率的电网电压不平衡条件下并网逆变器控制策略

针对电网电压不平衡条件下并网逆变器故障穿越问题,提出一种基于复功率静止坐标系并网逆变器控制策略,与传统旋转坐标系控制策略不同,本文提出的方法通过合并有功、无功功率脉动分量控制6个变量。利用两个调节系数将控制目标组合后实现具有限流功能的协调控制,不仅保证了电网电压不平衡情况下并网逆变器输出有功、无功功率连续调节,同时并网电流峰值维持在额定电流范围内,提高了系统可靠性。最后通过实验验证了提出方案的有效性。

Complex Power Based Control Strategy of Grid-Connected Inverter under Unbalanced Grid Voltage Conditions

The fault-ride-through issue for the grid-connected inverter is investigated under unbalanced grid voltage conditions.A new complex power based stationary-frame control strategy is proposed in this paper.Different from the traditional synchronous-frame control methods,our proposal is able to control six variables by combining the oscillating components of active and reactive powers.The coordinate control with the current-limiting capability is achieved with two adjustable variables by integrating the various control objectives.The proposal ensures the continuous adjustment of active and reactive powers,while the grid current operates within the rated value under unbalanced grid voltage conditions.Therefore,the system reliability is enhanced.Finally,the experimental results verify the effectiveness of the proposed solution.