Decoupling and power allocation control method for parallel operation of distributed micro-sources

Abstract

The invention discloses a distributed micro-source parallel operation decoupling and power distribution control method comprising the following steps: extracting a current io under a three-phase stationary coordinate system from a line, carrying out abc / dq conversion, converting the three-phase stationary coordinate system into a two-phase rotating coordinate system, thus obtaining a current direct axis component iod and a quadrature axis component ioq; calculating to solve the power coupling problems caused by resistive components in a line impedance; adjusting a sagging coefficient of the distributed micro-source in a parallel system so as to accurately distribute active power and reactive power, thus preventing circulation generation; the circulation outer ring refers to a power control ring, and the inner ring refers to a voltage current control dual-closed ring. The method can prevent circulation generation, can realize micro-grid large capacity and redundancy power supply, thus satisfying the micro-grid flexibility and reliability technical demands.

Description

technical field [0001] The invention belongs to the technical field of power electronics application, and in particular relates to a decoupling and power distribution control method for distributed micro-source parallel operation. Background technique [0002] The parallel connection of multiple inverters in the microgrid can increase the capacity of the system and enhance the stability of the microgrid. The droop control method is a non-interconnected independent control technology, which is often adopted because of its simple structure, convenient expansion, and reliable operation. In the low-voltage micro-grid, the locations of the micro-sources are dispersed, the line impedance is inconsistent and resistive, the power distribution is imprecise and the coupling is serious, and the control is difficult. Literature "Yunwei Li, Chingnan kao.An accurate power control strategy for power-electronics-interfaced distributed generation units operating in a low-voltage multibus mi...

AI Technical Summary

Problems solved by technology

Document "Lv Zhipeng, Luo An. Parallel power robust control of micro-source inverters with different capacities [J]. Chinese Journal of Electrical Engineering, 2012, 32(12): 35-42" and document "Lv Zhipeng, Su Jian, Li Rui, et al. A new method for parallel control of micro-source inverters with different power levels [J]. The improved droop control strategy proposed in Journal of Electrotechnical Society, 2013, 28(7): 191-198 can realize power distribution in proportion and is not affected by inductive impedance The size of the impact, but does not consider the resistance of the line impedance to cause power coupling problems

The literature "Wang Chengshan, Xiao Zhaoxia, Wang Shouxiang. Multi-loop feedback control strategy for distributed power inverters in microgrid [J]. Journal of Electrotechnical Society, 2009, 24(2): 100-107" will output the inverter The impedance design is inductive, which reduces the coupling between power, but this method is greatly affected by the control parameters

Literature "GUERRERO J M, DE VICUNA LG, MATAS J, et al. Output impedance design of parallel-connected UPS Inverters with wireless Load-sharing control [J]. IEEE Trans on Industrial Electronics, 2005, 52(4): 1126-1135" Introduce virtual impedance in the static coordinate system to design the impedance of the system, which improves the distribution effect of the system, but introduces high-frequency current interference

Images