中文摘要：

针对微电网中采用传统双环控制的逆变器并联系统功率均分精度较低以及输出电压和频率的偏移问题,分析了并联系统的功率均分机理及输出电压外特性,提出了一种基于虚拟阻抗和输出电压-频率瞬时值调节的逆变器并联运行功率与电压均衡控制策略.在传统的双环控制器中增加虚拟阻抗环,改善了输出阻抗特性,采用P-ω、QV下垂控制法提高了功率均分精度;同时加入输出电压幅值和频率调节环,对由下垂引起的电压、频率的偏移进行二次调节,能保证较高的输出电压质量.仿真和实验结果表明,所提出的功率与电压均衡控制策略使孤岛微网中的并联逆变器较好地均分负载功率,同时维持输出电压和频率为额定值,验证了所提算法的有效性.

英文摘要：

Considering the low power allocation accuracy of paralleled inverters system using traditional double-loop control and the voltage and frequency deviations caused by droop control in micro-grid, the power allocation mechanism and output voltage characteristics of a parallel system are discussed, and a balanced control strategy of power and voltage for inverters parallel operation is proposed based on virtual impedance and instantaneous output voltage/frequency regulation. Virtual impedance is added to existing control loops to improve the characteristics of output impedance, and the power allocation accuracy is enhanced with P-w, Q-V droop control. A scheme for regulating output voltage magnitude and frequency also participates in the loops to exert secondary regulation on the voltage and frequency deviations from droop control, and the higher output voltage quality remains. The simulation and experiment demonstrate that the proposed balanced control strategy for power and voltage makes the paralleled inverters share the load power better and preserves the rated output voltage and frequency in islanded micro-grid.