Aimed at the problems of slow maximum power point tracking (MPPT) convergence speed, low searching accuracy and susceptibility to falling into local optimum in the traditional grey wolf optimization (GWO) algorithm caused by multi-peak output power of photovoltaic (PV) arrays under partial shadow conditions, an algorithm with an improved Levy-flight GWO and variable-step perturbation & observation (ILGWO-VP&O) method is proposed. During the global searching, a new nonlinear convergence factor is put forward to improve the convergence speed and searching accuracy of the GWO algorithm, and the population with normal distribution is initialized to further improve the searching efficiency. Levy-flight is embedded to increase the randomness of global searching, so as to avoid the local optimum during the searching process. The VP&O method is used in the local searching to quickly capture the maximum power point at the global level. To verify the validity of the proposed algorithm, a PV power generation system was built for different published GWO algorithms and the ILGWO-VP&O algorithm, and these algorithms were experimentally verified. Experimental results show that the proposed ILGWO-VP&O algorithm has the fastest dynamic response speed, as well as the best steady-state control accuracy.
| 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 |