Frequency-Time Domain Characteristics of Radiated Electric Fields in a Multi-Terminal MMC-HVDC Station

A multi-terminal modular multilevel converter-based high voltage direct current (MTDC) system has become a popular research topic. Improvements to the voltage level and capacity have attracted increasing attention to its radiated electromagnetic disturbances. This paper discusses the measurements and analysis of the radiated electric field characteristics for an MTDC station. The control frequency causes the electric field to peak at multiples of 10 kHz, which reach approximately 80-90 dB mu V/m with an interval time of 100 mu s. In addition, the distribution characteristics and influencing factors of the radiated electric fields are also analyzed. The field decreases the fastest within 15 m as the distances from the hall increases. In addition, the electric field in the valve hall has obvious directionality under the influence of radiation structures and disturbance source characteristics. When the normal line of the loop antenna is perpendicular to the phase bus, the electric fields at multiples of 10 kHz are the largest. The radiated electric field intensity of this MMC station meets standard requirements.