Under over-resonant operating conditions, a CLLLC resonant converter with frequency modulation control will generate excessive current stress. On the basis, a control strategy based on phase-shift frequency modulation is proposed to suppress the current stress. A resonant current model under phase-shift frequency modulation control is established by the first harmonic approximation method. According to the soft switching condition and transmission power characteristics of the converter, the phase-shift values on the primary and secondary sides of the isolation transformer are obtained. Combined with the switching frequency obtained by frequency modulation control, the resonant current stress is reduced. Finally, a circuit simulation model and an experimental system of the CLLLC resonant converter were built to verify the analytical conclusions, and results show that the proposed strategy has a significant inhibitory effect on current stress.
| 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 |