Abstract: As an essential component of environmental protection equipment in coal-fired power plants, the selection and application capability enhancement of high-voltage power supplies for electrostatic precipitators significantly impact dust removal efficiency and emissions. To meet increasingly stringent "ultra-low emission" standards and the national "dual-carbon" strategy, and to address the efficiency limitations of traditional electrostatic precipitators under complex operating conditions—particularly when handling high-resistivity dust—research and application upgrades have been conducted on intelligent variable-frequency power supplies, control equipment, and systems specifically designed for electrostatic precipitators. The three-phase variable-frequency power supply, centered on intelligent technology, adopts an advanced AC→DC→AC→DC conversion topology in its main circuit, with a core architecture comprising a rectifier circuit, an LC filter circuit, an IGBT inverter, and a rectifier transformer. Operating at frequencies below 1000 Hz and utilizing SPWM modulation technology, this intelligent variable-frequency power supply converts three-phase AC power through rectification, inversion, step-up, and secondary rectification, ultimately delivering a highly smooth DC high voltage with a ripple coefficient of less than 3%. This technical approach fundamentally overcomes the inherent drawbacks of traditional single-phase industrial-frequency power supplies, such as high ripple, high energy consumption, and slow response, effectively suppressing electric field spark discharge and significantly enhancing corona power. Moreover, compared to high-frequency power supplies limited by single-phase topology and device capacity, the three-phase intelligent variable-frequency power supply achieves higher power ratings and operational reliability, making it particularly suitable for high-power application scenarios in million-kilowatt-level units and harsh top-side operating environments. Practical application results demonstrate that this intelligent variable-frequency power supply enables millisecond-level dynamic optimal matching with the electric field impedance of the electrostatic precipitator, thereby substantially increasing dust migration velocity. While stably reducing dust emissions by over 30%, the system achieves comprehensive energy savings of 30%–40%. In summary, with its exceptional electrical performance, significant energy-saving and emission-reduction benefits, and high level of intelligence, the intelligent variable-frequency power supply provides an advanced technical solution for enhancing efficiency and ensuring reliable operation of electrostatic precipitators in million-kilowatt-level units, holding broad potential for widespread application.