The admittance measurement of grid-connected inverters plays a crucial role in the stability analysis of renewable energy grid-connection. On this basis, a high-precision measurement method for the frequency coupling admittance of a grid connected inverter is proposed. First, the admittance measurement process based on disturbance injection is taken as a measurement process of deterministic components. Then, the signal with disturbance injection is considered as a broadband signal, and a method for measuring deterministic components of the broadband signal based on polynomial fitting is put forward. Finally, a frequency coupling admittance measurement framework for the inverter based on deterministic components is established. Simulation and experimental results show that compared with the existing methods, the proposed method can achieve high-precision measurement of broadband signals and accurately measure the frequency coupling admittance characteristics in various grid frequency scenarios, indicating its good applicability for the measurement of deterministic components.
| 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 |