Patent ID: 7425779

Claim:
A load sharing control method by using an unbalanced power to adjust active power, the method applying for a power system composed of at least two inverters coupled in parallel to provide AC power to a load through a bus, the method comprising the steps of: sampling an output voltage v o (t), a load current i load (t), and a current sharing command i load *(t) generated from a current sharing circuit; calculating a difference value i e (t) by comparing the sampled load current with the sampled current sharing command, wherein the difference value is expressed by i c (t)=i load *(t)−i load (t); integrating the product of the difference value i e (t) and the output voltage v o (t) during an output voltage cycle T, and then calculating an unbalanced power P unbal according to an equation P unbal = 1 T ⁢ ∫ T ⁢ i e ⁡ ( t ) × v o ⁡ ( t ) ⁢ ⅆ t ; establishing a relationship between the unbalanced power P unbal and a reference voltage V ref , wherein the relationship is expressed by an equation V ref =V setting +K 1 ×P unbal , and V setting is a preset initial voltage of the reference voltage V ref and K 1 is a gain value that is inversely proportional to the difference value i e (t); and adjusting the output voltage v o (t) of the inverter based on the unbalanced ∞power P unbal .