Positive inertia and negative inertia cooperative adaptive grid-connected inverter VSG power frequency control method

The invention discloses a positive inertia and negative inertia cooperative self-adaptive grid-connected inverter VSG power frequency control method, and aims to solve the problems that when a traditional VSG is disturbed, the power frequency adjustment time is too long or the overshoot degree is relatively large due to single inertia, or the VSG and an infinite power grid are out of synchronism during large disturbance and the like through optimization design of a VSG control strategy. By setting a condition threshold and automatically judging whether the inertia is positive or negative according to the frequency change, the VSG can recover the stable operation state as soon as possible under the condition of small disturbance or large disturbance, and the transient performance of the system is improved. 本发明公开了一种正惯量与负惯量协同自适应的并网逆变器VSG功频控制方法，通过对VSG控制策略进行优化设计，针对传统VSG受到扰动时，单一惯量导致功频调节时间过长或超调程度较大，或大扰动时导致VSG与无限大电网之间失步等问题，通过设定条件阈值及依据频率变化自行判断惯量正负，使得VSG不管在受到小扰动还是大扰动情况下，都能尽快恢复稳定运行状态，提高了系统暂态性能。