The modular multilevel converter (MMC) is a core component in the voltage sourced converter based high-voltage direct-current transmission, and its safe and reliable operation is crucial for ensuring the security of power supply. Insulated gate bipolar transistor (IGBT) devices in converter valves will produce significant electromagnetic interference (EMI) due to the high du/dt and di/dt, which can easily affect the normal operation of low-voltage control circuits and even lead to system failures. The gate driver circuit is directly connected with the highvoltage and large-current IGBT, and it supplies switch control signals to the system. Therefore, it is the most susceptible unit in low-voltage control circuits. The electromagnetic radiation from IGBT devices and the EMI issues within the gate drive voltage are investigated. First, it is clarified that the distance between the driver circuit and the power module is much less than the wavelength of electromagnetic waves generated by IGBT switching, thus focusing on the near-field radiation issues. With the consideration of the complex layout and wiring on the gate driver circuit and the presence of localized copper plating, it is revealed for the first time that the electromagnetic radiation sources on the gate driver circuit are composed of electromagnetic sources generated by the switching of IGBT devices and the electromagnetic scattering sources caused by copper plating on the gate driver circuit, which exhibit characteristics of multi-source interaction. Then, an actual converter valve sub-module was taken as a research object, and experiments were conducted under various switching conditions to fully and accurately determine the spatial magnetic field distribution characteristics of the converter valve sub-module in terms of location, frequency and intensity. In addition, the electromagnetic scattering characteristics on the gate driver circuit and the induced voltage at the driver signal port under the combined effects of electromagnetic scattering and radiation were also verified.
| 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 |