微电网中多功能并网逆变器的无线协调控制

多功能并网逆变器在实现可再生能源并网的基础上,还能利用其功率裕量补偿微电网内的谐波和无功电流。然而,单台并网逆变器所能投入的用于电能质量治理的功率容量是有限的。因此,如何有机地组织和协调微电网内的多台多功能并网逆变器,实现它们之间对网内谐波和无功电流的无互连线分摊,具有重要的研究价值。基于限幅控制,提出了一种能协调微电网内多台多功能并网逆变器分摊网内谐波和无功电流的无互联线控制策略。该方法通过对多功能并网逆变器所检测到的补偿电流dq轴分量进行限幅,实现谐波和无功电流在各台多功能并网逆变器之间按补偿容量分摊。最后,在一个微电网实验平台内,利用两台10kVA的多功能并网逆变器并联实验结果验证了所提方法的正确性和有效性。

Wireless Coordination Control of Multi-functional Grid-tied Inverters in Microgrid

Compared with normal grid-tied inverters, multi-functional grid-tied inverter (MFGTI) can actively provide auxiliary services to enhance the power quality of microgrid. However, the available capacity of only one MFGTI for power quality enhancement is usually not adequate. Therefore, it is a challenging issue to organize and coordinate many MFGTIs in a microgrid to share the harmonic and/or reactive current without communication wire. On the basis of limitation technology, a strategy is presented to share the harmonic and reactive current in microgrid. Using the limitation threshold of detected compensating currents on synchronous rotating dq frame, the MFGTI can partly contribute their available capacities to compensate harmonic and reactive current. The experimental results performed on a microgrid demonstration verify the validation and feasibility of the proposed control strategy and algorithm. This work is supported by National High Technology Research and Development Program of China (863 Program) (No. 2011AA050204) and National Natural Science Foundation of China (No. 50907060).