A control method of reactive power equalization of parallel distributed power sources

Abstract

The invention relates to a control method for reactive power sharing of parallel distributed generation. The control method comprises the following steps: calculating voltage drops of distributed generation power transmission lines and adding the voltage drops to reactive droop control; compensating the voltage drops of the power transmission lines with the voltage compensation quantities of the power transmission lines and improving the distribution accuracy of reactive load by the distributed generation; measuring voltage amplitude values of distributed generation access points, and feeding back the voltage amplitude values of various distributed generation access points to the reactive droop control, and effectively tracking voltage change of the distributed generation access points; and carrying out proportional-integral (PI) adjustment on the voltage compensation quantities of the power transmission lines and the compensation quantities fed back by the voltage amplitude values to obtain the compensation quantity of an initial value of a reactive droop curve, translating the droop curve and adjusting a stable operating point of the system, so that the voltage amplitude values output by the parallel distributed generation are equal. The reactive power distribution problem of the parallel distributed generation is improved; reactive circulation between the parallel distributed generation and the parallel distributed generation is reduced; and a micro-grid runs relatively efficiently and stably.

Description

technical field [0001] The invention relates to a parallel distributed power supply control technology, mainly aimed at equal sharing of reactive power output by a parallel distributed power supply using power droop control, and specifically a control method for equal sharing of reactive power of a parallel distributed power supply. Background technique [0002] As an effective carrier of distributed power, the microgrid can operate in four operating states: island, sudden load change, grid-connected, and switching between two operating states. In addition to the functions and parallel operation, it is also necessary to have some control functions according to the special requirements of the microgrid system, such as active power-frequency droop control function and voltage-reactive power droop control function. Multiple distributed generation (DG) in the microgrid operate in parallel, and a peer-to-peer control strategy is mostly adopted. The so-called peer-to-peer control...

AI Technical Summary

Problems solved by technology

[0005] Today, droop control has been widely used in microgrids, especially in peer-to-peer microgrids. However, due to factors such as line impedance differences, output voltage amplitudes, and microgrid complex structures, traditional droop The reactive power output by the distributed power supply is difficult to achieve the effect of equal sharing, which seriously affects the reasonable distribution of reactive power. When the situation is serious, a large reactive power circulation may be generated between distributed power sources

Images