With the continuous increase in new energy penetration, the impedance interaction between a grid-connected inverter (GCI) and a weak grid is easy to induce small-signal oscillation instability. To solve this problem, the limitations of the existing voltage feedforward impedance reshaping strategy are analyzed in this paper at first. Then, an adaptive voltage feedforward impedance reshaping strategy is proposed. This strategy utilizes simulated anneal-particle swarm optimization algorithm to optimize the feedforward path parameters off-line under sample conditions of different values of output power and grid impedance, and polynomial fitting is used to cover the continuous full operating range. By deploying the fitting relationship in the inverter, the feedforward path parameters can be adjusted adaptively according to real-time power and grid impedance. The proposed adaptive strategy can ensure a better stability margin of GCI under conditions of different values of output power and grid impedance, and the dynamic performance of the system is considered to some degree. Finally, experiments were carried out on an OPAL-RT semi-physical experimental platform to verify the effectiveness of the proposed strategy.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |